Orochimaru w/ET general:
Spoiler:

I think he only needs Edos for Danzō and the three paths. He clears the rest with varying difficulties without Edo Tensei.

Orochimaru op said:
Sasori

Manda should be able to fight for a bit even if he's scratched, and he has the option of going underground to avoid Sasori's attacks, meanwhile Manda can cause heavy casualties to Sasori's puppets due to its strength and size. In addition Orochimaru himself seems to be immune to poison, and his Hydra overpowers Sasori's arsenal.

Hebi Sasuke

Close fight, Sasuke is crafty and dangerous but I think Orochimaru overall has the more powerful arsenal. Orochimaru has better mastery of the white snake power and Sasuke only has Kirin as an option to deal with Yamata. Neutral knowledge Orochimaru in a tough fight.

Kisame
There are three stages to Kisame's fights; on the ground (kinjutsu and occasional Suiton if water is available like against Asuma) on the lake (kinjutsu and more frequent Suiton like against team Gai) and inside the waterdome (Bee).


Kisame on the ground will be overwhelmed quickly, Summons are a problem without ninjutsu, Orochimaru's sneak attacks are a problem, bindingsnake glare is a problem. On the lake he stands in a better position as Orochimaru's underground tactics and snakes will be tougher to land and he can dive underwater and try to dictate the battle from there.


Kisame is going to be constantly pressured from match start by snakes, Kusanagi, and poison while on land. If he finds room to use his lake (or start with it like we've seen him do against team Gai) then he gets a breather. From there Orochimaru amps up the tempo with large summons that could likely swim (Manda 2 could swim) and Kisame gets overwhelmed; 1000 sharks is matched somewhat by 1000 snakes and Daikodan is blocked/meatshielded by Manda/Hydra/Rashomon, the rest of Orochimaru's jutsu (Kusanagi, Oral Rebirth, giant snakes, poison) trump Kisame's (shark bullet, water prison, feeding sharks (few in numbers) meaning Orochimaru is putting the pressure on Kisame on his lake.


Orochimaru is also smarter, more knowledgeable, more experienced, has more unknown jutsu hype, knows more elements, has a perfect score in genjutsu, etc. Plus Kisame said Jiraiya was stronger than him, implying the reason is because he's a Sannin, and was compared to PI Kakashi favourably (something like mid-diff) whereas Orochimaru was so far above PI Kakashi that they were incomparable (neg/low-diff).


Overall a low/mid diff fight for Orochimaru, if Orochimaru used more jutsu that were absorbable, or wasn't as indirect in his fighting style Kisame would have stood a better chance.


3T Itachi vs Deidara:
Spoiler:
C1 can be dodged, C4 can be seen through and dodged as we've seen with Sasuke (he got caught due to being feinted which is unlikely to happen to Itachi).

C2 is 50/50 seeing as while it's faster and has larger aoe Deidara also had the advantage of the placed mines which were the main reason Sasuke struggled.

There's the possibility of Itachi closing the distance before Deidara takes to the air, and then there's 3T which Deidara has knowledge of and a supposed counter.

I would usually give the slight edge to Deidara due to C2 spam being more dangerous than Itachi's arsenal and Deidara having genjutsu resistance but with the distance here being 5 meters that's not guaranteed.


Itachi vs Minato
Spoiler:
Itachi and Minato are similar in that they're both young geniuses who didn't live up to their potential, who both possess excellent reactions with instant/near-instant offense and defense (through MS and FTG). The issue for Itachi is that his MS in comparison to Minato costs much more chakra and has worse drawbacks which is the decider in this fight imo.

Minato's reactions and FTG mean Amaterasu and Totsuka are unlikely to land, they also mean Itachi can't corner him in CQC to land Tsukiyomi since Minato can keep teleporting
With FTG-using KBs thrown in the mix and Minato's superior stamina it's a matter of time before Itachi is overwhelmed.

Minato also had very little panel time, at least in comparison to Itachi so he might have other stuff up his sleeve.

In terms of portrayal Minato beat Obito who Itachi couldn't beat in his lifetime when he had every reason to.


Yamato's statement
Spoiler:
I heard there was another translation where it's said differently, but I don't know.

If not, you could and say that it wouldn't make sense that his power would be praised in relation to Itachi if the gap was significant, and that this piece of portrayal is more recent and should take precedence. Or you could say that the plethora of evidence showing Kisame being inferior to Itachi and Kishi not giving an explanation for this supposed sudden power-up of Kisame (the author could have had Kisame as someone who was hiding his true power or that he was playing weak or something like he made excuses for Hashirama like people didn't believe how strong he was, etc) points more towards Kisame being powerful just enough to be relevant to Itachi.

The issue is if Kisame did get retconned then all his past actions need to be explained (cucking to Jiraiya, saying Deidara was one of the stronger Akatsuki, etc), and since his introduction until his death he was built-up as Gai's rival, so did Gai get retconned too? Kisame being retconned to be much stronger than he was also can be argued to serve no purpose in the story as a side-villain and the author is unlikely to have an incentive to do that, and imp he probably didn't.


Kimimaro vs Asuma
Spoiler:
Tough one, Asuma was portrayed as decently stronger than his individual students in the war arc and is stated to be 'close in power' to Part I Kakashi - which would put him as a skilled/high Jonin since Kakashi is one of the strongest Jonin. Kimimaro on ther other hand was kept up with by the kids, however he could still easily subdue Jugo (I rank Jugo as average Jonin or lower at his best) but then again the gaps between Jonin levels is massive anyway. Kimimaro has some sketchy portrayal due to the implications of him being relevant in a Kage battle, being compared to Hebi Sasuke and being sick (so some of his hype might be referring to his stronger self). But even then those can be explained somewhat (Orochimaru meant absorbing his body then fighting Hiruzen rather than Kimimaro himself being there, being >> Jugo is not impressive when even Suigetsu could do it and Hebi Sasuke subdued both Suigetsu and Juugo effortlessly while Kimimaro only subdued Jugo).

I have Asuma mid-high diff by an extending Hien or his Katons, and he could probably outlast sick Kimi. Though I think it can be argued otherwise


NLF
Spoiler:
We don't completely ignore them as that's unfair, however we work with the information available while making sure it doesn't contradict the character's and the jutsu's portrayed strength.

Daikodan is said to get bigger the bigger its target is, we saw it lose to Hirudora but the stress there was on Hirudora not having chakra rather than being the more powerful technique. That tells me that techniques (that have chakra) and are on Hirudora's destructive level would not overpower Daikodan's absorption. If Hirudora was too strong to be absorbed, Kishi would have had Gai overpower it directly, and there'd be no point in the whole "it's not made of chakra".

This is not to be confused with Daikodan's own firepower, as the whole idea of the technique (and absorption in general) is that it ignores firepower entirely (up to a certain point). Now the question is since Daikodan is an offensive projectile jutsu what is its actual firepower and how much damage does it do?

We know Daikodan is a much bigger version of the normal shark bullet, so based on that we can conclude its firepower is much stronger, but obviously its firepower is weaker than Hirudora's because the latter overpowered it.The shark bullet seems to be targeted/it chases the enemy rather than a straight line so maybe that also applies to the bigger version (which would be interesting if a shinobi were to dodge it he wouldn't get rid of it).

Other than that there clues like Daikodan's hype/portrayal as an absorption technique is not on the level of things like Preta path for example because the latter could absorb Senjutsu without problems and has better hype so the same way those characters/techniques aren't invincible so would Daikodan not be. Preta seemingly couldn't absorb solid material like Gaara's sand, so that puts in the question of whether the shark bullet can be blocked by solid ninjutsu.

Daikodan is an offensive projectile meaning the end goal is to harm the enemy, based on common sense an average shinobi getting hit cleanly by Daikodan and surviving wouldn't make sense if his smaller shark creations could rip apart human flesh.

Yata made Itachi "invincible" and was called an "ultimate defense" while he had V4 Susano'o up, so one can make the argument that Yata is above V4 Susano'o durability (what's the point of Susano'o carrying a shield thats weaker than its body, and why would a shield that's weaker than its wielder's body be hyped up as an ultimate defense instead of that supposedly weaker body?).

By scaling the Totsuka was Orochimaru's downfall and something he seeked but couldn't find, Yata by hype is placed in that same category, meaning Yata > Orochimaru's defenses. For example Yata should outperform Orochimaru's Rashomon against KN4 TBB, and likely by a decent bit too. When it comes to things like Jinton for example it depends on which you believe has higher portrayal or is more valuable between Yata and Jinton, and Itachi's own portrayal in comparison to Onoki and how much their respective techniques account for their overall power (debatable but there's information to infer).

Frog Song can likely be countered by partner method, the author goes out of his way to highlight specific counters to powerful techniques. Tsukiyomi is immune to partner method and Kishi made sure to show us that when two PJ said it would one-shot them if it landed, and Naruto said everything happens in an instant so you can't break out. That didn't happen with Frog Song. You could say Senjutsu makes it hard to overpower but then it's a matter of Biju chakra vs Sage chakra. You could say the mechanism by which it works implies it's a one-shot once it happens since "it seals the mind and body" or that the partner (biju) would also be caught - those arguments aren't baseless but imo:
1. there is no incentive to believe it will one-shot; SM Jiraiya is not cleanly portrayed above Killer Bee.
2. the arguments for it being broken I feel are more supported by evidence rather than giving the benefit of the doubt to the sages.

Koto is more straightforward, we saw it can work on people on Edo Itachi's level but the issue is Shisui's portrayal isn't defined in the manga and there is very little information for us to conclude how strong he actually was. So this makes it difficult to rate how practical or to where a logical limit should be drawn for Koto.

Overall I think it's important to remember the practicality of these techniques; they first have to land on the opponent for this discussion to be needed (from a practical "who's stronger" perspective), Jiraiya has to prep SM and then prep frog, Itachi has to establish eye contact, Daikodan has to hit the target, Koto has to be cast etc. When we take these things into consideration they make the conclusion more likely to be close to the truth.


Jiraiya vs A3
Spoiler:
Jiraiya vs A3:

Portrayal wise, KCM Naruto struggled to defeat A3, but his SM incarnation (which is weaker) defeated A3 with some knowledge advantage but it was only a clone and it was a straightforward defeat. SM Naruto was portrayed as superior to Jiraiya but not to the extent he'd lose to his clone. Jiraiya defeated Kisame and Konan quickly and in base and is portrayed superior to Hiruzen who's stated to be the strongest of the five kages. One might disagree and say Jiraiya won't stalemate the Hachibi but we can't ignore that Deidara (who's portrayed as so much weaker than Orochimaru who's Jiraiya relative to the extent he wouldn't make Orochimaru struggle) literally knocked out the three tails and several fodder shinobi could restrain the wild Hachibi (wild is an important distinction so we don't get carried away and apply all the feats of Bee to the Hachibi). If we say "Deidara just had the firepower it doesn't mean Jiraiya can do it" this implies it is a match up issue rather than an overall level of strength issue which can be easily turned around and used against A3's accomplishments (he only stalemated the Hachibi because of his stamina not because he's a match for him). What's more is that we've already seen Base Jiraiya defeat KN4 while technically he shouldn't have the firepower to do so. Overall all of Jiraiya's praise and hype puts him above A3 even if slightly.

How the fight goes down: we look at how they fight; A3 is a straightforward cqc fighter who engages in close range and relies on his strength, speed and durability to win while Jiraiya is a mid to long range fighter who relies on large aoe, traps and taking advantage of locations. So basically they are the opposite of each other. The fight will mostly be A3 trying to close the distance and kill Jiraiya in cqc while Jiraiya falls back and uses traps to slow A3 down/provide openings
or his large aoe that isn't easily dodgeable.

In a neutral fight Jiraiya will start in base and have manga knowledge, even if we don't think Jiraiya knows about the lightning shroud and the Raikage's strong body (Tsunade did iirc) then Jiraiya still has the advantage here because Jiraiya has more abilities A3 doesn't know about than A3 has abilities Jiraiya doesn't knows about; this matters because throughout the course of the fight A3 who's straightforward will be figured out quickly as opposed to Jiraiya who can do dozens of things and fight in many different ways. Jiraiya will likely figure out A3's abilities and his strong body during the initial exchanges by using his mid-range attacks like Yomi Numa, FCD, Shadow manipulation etc and he likely won't be in danger because he doesn't prefer CQC anyway, from this point on Jiriaya will know if his arsenal in base is a match for A3 or if he needs SM. You might argue that Jiraiya shouldn't get enough time to figure all this out but we've literally seen the opposite happen to A3 against the alliance who had enough time to mount defenses that failed and gave them that knowledge. Jiraiya might not have fodders to support him but those fodders are nothing to Jiraiya in the first place.

Contrary to popular belief, Jiraiya can buy time for SM other than just Gamaken. He can set up dozens of traps like shadow manipulation, KB distractions, smoke bomb/toad diversions, Boss Summons leaping/jumping out of range while his detection barrier is active all together to reach SM. If we believe Jiraiya can't move while his hands are clasped for the ritual then that means it takes him very little time to reach SM (against Pain he was only perfectly still from the time Gamaken was falling until Gamaken reached the ground) and if we believe it takes him longer (i.e from the moment he clasped his hands and activated his barrier) then that means despite him taking longer to reach SM he can still move around freely. A3's problem here is that he's strong and durable but if the distractions are slowing him down he can't do much about them since he's pretty straightforward and doesn't have many options.

Once Jiraiya reaches SM, Frog Song definitively defeats A3 and now Jiraiya can do everything he did before to slow down the Raikage but much better since he has Senjutsu to enhance his base jutsu, new Senjutsu techniques (Geomon) and Ma and Pa who can target him with Futon to blow away the shroud (the Futon is dodgeable to A3 but them already knowing that would only use it after a distraction/blindside and we've seen A3 hit by Futon in canon). Blowing away the shroud might not be enough to weaken A3's durability enough so that Jiraiya can directly kill him, but it would make it easier to slow the Raikage even more than before and allow Frog Song to be executed. We must remember that in SM Jiraiya could escape shared vision and snag a body, A3 might be faster than the paths but he isn't as tough to deal with overall.

As for A3's speed it's is not so astronomical that Jiraiya will be overwhelmed by it if Dodai and those fodders didn't, and that's not an outlier because we've seen in the manga that faster characters tend to overwhelm slower characters after a while rather than right from the get-go:

1. Kurenai dodged Itachi's strike and blocked his kick, but was eventually overwhelmed and blindsided by Itachi's shunshin speed (when he went behind her without her knowing what happened).
2. V1 A was praised on panel of having speed that is >= Minato's but was being kept up with by Suigetsu and Jugo who could not only intercept him (interception feats usually aren't reliable, but this one in particular was highlighted by Shi as impressive) but block him too (Jugo). However they still eventually got overwhelmed by the speed (Juugo commenting on Raikage's speed and Raikage dodging him point blank and blindsiding him with shunshin+elbow).

A4 and A3 are both fast and durable, but A3's emphasis has always been on his durability (strongest body, tanks FRS, etc) while A4's was on his speed (fastest man, Minato's rival, Shi's commentary). More importantly, when A3's speed was emphasized it was through his reflexes to dodge FRS from close range rather than overwhelm his opponents with his speed, just like the emphasis on A4's durability was minor (surviving Chidori, Sasuke's sword bouncing off) rather than being emphasized as someone really tough to damage.

For Kisame vs A3 I said that Black Lightning might make a difference, but here I don't think it will. The reason for that is because A3 never bothered to use it against SM Naruto/the alliance shinobi which implies to me that people who are close to SM Naruto wouldn't have this jutsu make a difference against them either. In Kisame's case he is just much weaker than Jiraiya and Naruto so it's optimistic to assume that for him.
So yeah, Jiraiya wins with high difficulty.


Tsunade vs Hebi Sasuke
Spoiler:

Tsunade vs Hebi Sasuke:

Comparing their portrayal Hebi Sasuke and Tsunade are on the same general level/tier. The reason I think they are is that we know Jiraiya is portrayed above Tsunade because Shikaku said Sages are above anyone in the village, and Fukasaku said only Jiraiya could have done that much against Pain in front of Tsunade. Naruto had to surpass Jiraiya and not Tsunade to face Pain. This also fits with Naruto >= Sasuke > Sakura theme and takes into consideration that her support abilities and accomplishments are included in her portrayal (so if she's on the same level as Orochimaru/Jiraiya with support/medical ninjutsu logically she would be below them without it (i.e fighting ability only). My tiers are narrow but they still give a decent idea:

Tier/level 1:
SM Naruto
SM Jiraiya

Tier/level 2:
Tsunade

Next, we know Jiraiya is portrayed as decently superior to people like Kisame (and therefore people around Kisame's level), while it's true Jiraiya had a location advantage in the hotel Kisame still shouldn't have been helpless if he was close in power to him. However we also know that Kisame is still below Tsunade because he admitted inferiority to the Sannin collectively:

Tier/level 3:
Kisame

So now we have people solidly above Tsunade (Jiraiya, SM Naruto and people relative to them) and people solidly below Tsunade (mid-Akatsuki, Masters), the only question is who fits in and fills up Tsunade's tier? i.e which characters are portrayed as above mid-Akatsuki/Masters but still below SM Naruto/Jiraiya/MS Sasuke etc?

Hebi Sasuke already fought a mid-Akatsuki in Deidara, and had every disadvantage against him (no KI, match-up disadvantage (ironically people claim Sasuke had a match up advantage going against the author's words), Tobi laid the mines, genjutsu counter) yet Sasuke still won and the author literally had Sasuke say "even if Raiton didn't work I had a back up plan" as if to tell people "no you can't use Raiton as an excuse". Sasuke didn't use Kirin. Even from a story perspective this served as the "warm up" fight for Hebi Sasuke and for us to see a "glimpse" of his power before his actual real battle against Itachi. It's why Sasuke kept getting praised for his speed, sharingan, Raiton etc throughout the fight, Deidara was used to hype Sasuke.

Another way to look at it is that Sasuke had every disadvantage against Deidara and came out on top, meaning he's a level above him. Similar to how Itachi had every disadvantage against Hebi Sasuke (lack of KI, planned the fight, had to fight Orochimaru's hydra as well, etc), meaning Itachi was a level above him.

Deidara is also hinted by Karin to be inferior to Orochimaru and we know he's inferior to Sasori so he competes with Kisame/Kakuzu.

So now we have:
Level 1:
Sick Itachi
SM Naruto
SM Jiraiya


Level 2:
Tsunade (below Jiraiya)
Hebi Sasuke (below Itachi)

Level 3:
Kisame (below Tsunade, below Jiraiya)
Deidara (below Hebi Sasuke, below Orochimaru)
Kakuzu

Other people you can fit in in Tsunade's tier are people portrayed below level 1 but above mid-Akatsuki and masters level: Like A3, A4, Hiruzen, Sasori etc. They might not be equal but they're comparable.

Now there is the comment of Karin telling Sasuke "Someone who beat Orochimaru shouldn't have struggled with the likes of Deidara" and Sasuke told her it was because Orochimaru was weakened. The thing is, we know why Sasuke "struggled" with Deidara: the author went out of his way to highlight that Sasuke had no KI, we saw Sasuke take damage and lose the ability to fly because of Tobi's interruption, we were directly told that Deidara is a bad match up for Sasuke, we found out Sasuke didn't use his trump card and we were told Sasuke still had a back up plan anyway. So all of these are clear reasons the author dedicated panels to highlight which show us why Sasuke struggled against Deidara. If Kishi wanted to portray Deidara as close to Hebi Sasuke he could have simply wrote the fight without those things, but he didn't and we shouldn't ignore that.
Sasuke was informing Karin that his BoS version was lucky Orochimaru was sick, not that his Hebi version struggled against people Orochimaru wouldn't struggle against.

The point here is that there's no way Deidara (or those on his level) are on the same tier as Hebi Sasuke.

Excluding her support role, against the Susano'o clones Tsunade was portrayed as below Onoki (at least post-will) and comparable to A4 (he implied she was getting sloppy and he had one arm which points to his superiority but he still got caught by genjutsu which puts her back up there with him) and above Mei (who was getting overwhelmed).

Generally speaking they should be on the same level and comparable, the question is who should have the edge? If I had to choose I'll give a slight edge to Tsunade because I think it's slightly optimistic to assume Sasuke surpassed and can defeat a Sannin because his next power up the Mangekyo Sharingan is supposed to be equal to SM Naruto who has just surpassed the Sannin. The idea of Hebi Sasuke for me is that it is a bridge between Wind Arc Naruto and SM Naruto. Wind Arc Naruto is comparable at best to BoS Sasuke albeit weaker while SM Naruto is comparable to MS Sasuke. Hebi is in between these two stages and he ended up losing his Hebi powers as they were a red herring to the story and his development (Orochimaru and his powers are evil). So basically it doesn't make sense that there is a power up of Sasuke where he can defeat one Sannin and lose to the other two, what makes more sense is that he reached the minimum of Sannin-level and can give a really good fight to Tsunade but ultimately lose. I also don't think he'd do as well as Tsunade did against Madara even if most of what she did was off-panel.

Now we move on to how they fight: Hebi Sasuke is a close to mid-range fighter who relies on his swordsmanship and Raiton variants to damage the enemy, his Katons and snake hands/meatshields are used in close to mid-range for offense/defense and has access to high-level offensive and defensive techniques in the form of Oral Rebirth, Kirin, and his CS that while are very powerful they exhaust his chakra or require some time to set up. He also has access to a boss summon in Manda.

Tsunade is mainly a CQC fighter that relies on her top notch Taijutsu, paralyzing through Rashinsho, resilience, top notch regeneration, adeptness at evasion and most importantly her strength, her Byakugo increases all her stats on top of automatic regeneration and she has access to Katsuyu who is useful both in battle and as support although she is inconsistent in summoning it for battle. She also seems to have high stamina and a gravitation towards attrition battles.

How the fight goes down: First off we agreed their portrayal is close to each other meaning regardless of who wins it won't be without effort or without big jutsu being involved, so right off the bat Tsunade one-shotting Sasuke in the first CQC exchange or Sasuke beheading her with Chidori Eiso are out of the question. Tsunade will likely engage in CQC and so will Sasuke who will be at a disadvantage. The reason Tsunade will have the upper hand in CQC despite Sasuke's sharingan, emphasis on speed, CS2 amp, Raiton, kinjutsu is because of her superior skill, much superior strength, Rashinsho, emphasis on evasion skill, resilience and durability which are overall a better and superior CQC toolkit than Sasuke's. Sasuke's skills will likely be relevant here for defensive purposes however, allowing him to survive her onslaught with his sharingan/speed/CS2 and gain some distance, at worst Sasuke wastes one Oral Rebirth but I doubt it. Her Byakugo is also a better enhancement than CS2 in CQC since not only does it boost her stats and make even much more dangerous due to her strength but it heals her from anything that doesn't kill her instantly from Sasuke in a swift fashion that barely slows her down. From there Sasuke will likely go for mid-range shurikens, Katons and using snakes which would be countered by Tsunade's strength/evasion and if not then by Byakugo which Tsunade would have activated by now due to knowing she'll need it to face someone with Orochimaru's powers and/or to handle Sasuke's Katon spam. At any rate like I said before their portrayal is close so Byakugo will definitely be activated before (if) she's killed.

At this point Sasuke would have realized that even if he were to go CS2 and attempt to kill Tsunade in CQC it likely won't work due to her strength/regen that he's seen before/is currently witnessing making his only remaining options genjutsu, Manda and Kirin.
When it comes to genjutsu and Tsunade, there are points in her favor and points that are in Sasuke's favor. In Sasuke's favor, we have seen him use genjutsu to land openings on Deidara and could (somewhat?) restrain Orochimaru. More importantly Sasuke has the ability to mind control summons and has a feat of doing just that to a Sannin boss summon no less. Some will say Sasuke only got Manda because he was distracted, Sasuke only controlled Manda for like a split second and only made him open his mouth which doesn't mean he can fully control his actions, controlling Manda cost Sasuke a lot of chakra, etc. But realistically speaking these are all excuses supported by zero evidence fro the manga or databooks, in fact the databook goes on to praise Sasuke for this skill and more importantly says that Sasuke displayed a glimpse of what Madara did when he controlled the Kyuubi i.e the reference for his feat was the feat of mind-controlling the Kyuubi (which obviously doesn't have any of those made up weaknesses).

In Tsunade's favor, we have to remember that Sasuke's genjutsu is not as strong as Itachi's and therefore less impactful, meaning Tsunade shouldn't struggle as much as Orochimaru to break it and risk losing a limb. Sasuke also doesn't tend to try and force eye contact in cqc as much as Itachi does and his genjutsu is mostly used for openings (likely because his genjutsu isn't as strong as Itachi's). Some optimistic assumptions for Tsunade would be her and Katsuyu sharing chakra/informing the other when genjutsu is used and then breaking it, but this is unlikely since I'm a firm believer in the idea that if the author highlights certain counters to a technique (like 3t) to hype it then we can't go and assume what other counters are just because the mechanism seems like it works, kind of like how Pain "constantly pumps chakra into the paths" but was never portrayed as immune to genjutsu. In Tsunade's defense however, we don't know how practical/successful would controlling Katusyu be, technically speaking if she's being occupied by Manda (which I'll get to next) then Sasuke might have an opening to genjutsu Katsuyu but the problem is Sasuke himself will be occupied with Tsunade and while this might mean the slug and her princess can't save each other from genjutsu (because each one is occupied fighting) it still likely isn't such a big factor since we established Sasuke's genjutsu isn't that dangerous looking at its portrayal and the fact that Sasuke may not have an opening to use it if Tsunade is charging him with Susano'o-busting, Magatama-tanking, Katon-swatting momentum. Another issue is that Sasuke doesn't have knowledge on any of Katsuyu's abilities so even if he's successful in controlling her it won't be that dangerous.

Manda and Katsuyu: By portrayal, Manda and Katsuyu are in the same league along with Gamabunta. Therefore logically speaking if we apply the deadlock the difficulty at which Katsuyu kills Manda should be about the same as the difficulty of Manda killing Gamabunta - so the common suggestion that Katsuyu "can't be killed by Manda, he can't do anything to her!" isn't true when Gamabunta could hold his own against Manda for a while. Also, Katsuyu in canon couldn't achieve that much dominance over Manda and Tsunade delivered the finishing blow; if Katsuyu could get rid of Manda that easily Manda wouldn't have occupied both summons and needed to be defeated by Tsunade.

Tsunade didn't opt to summon Katsuyu against Madara to help her fight, she only summoned her for support reasons, so did Sakura in the war arc. From the way the Madara fight and Tsunade's feats and portrayal in that fight were drawn, it doesn't seem like the author wants us to think that Tsunade was not fighting at full power. One could say this fits with Katsuyu's support abilities being so important implying that's what she's mainly used for. Tsunade did opt to summon Katsuyu against her fellow Sannin Orochimaru, but Orochimaru relies on summons anyway and that could be due to the summon deadlock. Even when Katsuyu was summoned.

However, a simple counter to the above within the context of this fight is that even if Tsunade wouldn't summon Katsuyu, she definitely will when Sasuke summons Manda anyway, and if Tsunade finds an opening against Manda she will one-shot the snake with her Byakugo-enhanced strength while Sasuke is gonna have more difficulty handling Katsuyu.

Now that we're past genjutsu and summons, at this point the likely outcome is that Manda gets killed by Tsunade or Katsuyu's acid while Katsuyu is de-summoned or remains on the battlefield while Tsunade heals from the injuries and Sasuke is fatigued from all the fighting and likely due to possibly having survived a punch from Tsunade due to Oral Rebirth, Sasuke used Oral Rebirth in an offensive manner against Itachi but he had the momentum then and it was part of his plan due to his knowledge, here the only thing he'll benefit from it is the extra life.

At this point the battle is over one of two ways, either Sasuke dies before he gets to set up Kirin from an incessant onslaught from the never-tiring Tsunade giving her a high difficulty win, or he manages to prep it. If he manages to prep it it would be weaker than what we saw against Itachi but still relevant enough to kill Tsunade, at this point Tsunade's only answer would be to have the Katsuyu that was already there (Katsuyu didn't de-summon since Sasuke presumably immediately went for Kirin) engulf her and protect her, this could work if we consider how durable Katsuyu is and that Kirin will be weaker than the one we saw, all on top of Tsunade's Byakugo. Or it could not work and Tsunade dies. However the problem with this is that the portrayal of Kirin
specifically highlighted it's striking speed which implies most characters wouldn't get the chance to mount a defense, on the other hand one could argue the emphasis on it's striking speed is telling us "you can't dodge the aoe because it hits fast enough and big enough" not "you can't try to mount any defense of any shape" but that is too optimistic for Tsunade. If Tsunade is conveniently atop Katsuyu than that's lucky for her too.

With all that said though, I think it's more likely Sasuke doesn't get to set it off in the first place due to the incessant pressure he'll be getting from Tsunade that he didn't get from Itachi. If Itachi wasn't coughing blood, injured and wanted to kill Sasuke he wouldn't have gave him enough time to set up the Katons, jump up into the big stone, etc.

What really makes me lean towards Tsunade is the fact that Hebi Sasuke had two full on-panel one on one fights to show everything he had, Tsunade never had a one on one fight, was rusty and hemophobic in one fight and had a team and lots of off-panel performance in her other fight. At most we can say Sasuke can use some more minor snake abilities from Orochimaru but he's had his chances to showcase everything to use and he doesn't really have any hype to suggest important parts of his arsenal were not shown. Tsunade on the other hand has taught Shizune and Sakura how to use poisons offensively, participated in an entire war as a fighter before she became a medic, has been implied to be able to use medical ninjutsu offensively (against Orochimaru) and could have some small elemental jutsu here and there.

Imagine if the Deidara and Itachi fights were replaced with fights where Sasuke was rusty/had no will to fight/scared of blood and the other one in a team with five others where most of his on-panel showings are snapshots of CS2 Chidori through the opponent.

To conclude, it's a close battle but I lean towards Tsunade with high difficulty.


Jiraiya vs MS Sasuke:
Spoiler:
MS Sasuke is portrayed stronger and has a stronger arsenal, he also matches up well against Jiraiya which is saying a lot since Jiraiya is so versatile and has so many options.

Snakes and genjutsu counter toads, Raiton counters Yomi Numa, Amaterasu counters any Katon, Susano'o blocks most Jiraiya's attacks, what's more is Jiraiya is dealing with someone who is trigger-happy with the MS, Jiraiya can only hope to sense and maybe do something about Amaterasu/Susano'o Arrows for so long before he's tagged or overwhelmed, MS genjutsu is still a problem and Jiraiya can't freely try to keep his distance with summons since Sasuke also has those in addition to flight.

Jiraiya loses even if he starts in SM, if he starts in base Sasuke wouldn't even need to resort to MS for a long portion of the fight since his base self is good enough a match-up against Jiraiya that he can afford to fight without MS for a while.