So yes, spoiler if you aren't up to date on the Japanese manga.
Itachi's grand plan is to steal Sasuke's sharingan. We know this is possible as we have seen that Kakashi was gifted the sharingan of his dying friend Obito. Going well so far, but consider that Sasuke only has the basic sharingan, upon implanting these into himself Itachi would lose all of the abilities gained from having the mangekyo sharingan. He'd no longer have Tsukuyomi, Amaterasu or Susanoo; it was mentioned that Madara's transplant took place after both he and his brother had unlocked the full potential of the sharingan and as such no similar loss of power happened there.
Does Itachi plan to somehow kill his already deceased best friend all over again in order to regain the mangekyo sharingan?
Itachi's grand plan is to steal Sasuke's sharingan. We know this is possible as we have seen that Kakashi was gifted the sharingan of his dying friend Obito. Going well so far, but consider that Sasuke only has the basic sharingan, upon implanting these into himself Itachi would lose all of the abilities gained from having the mangekyo sharingan. He'd no longer have Tsukuyomi, Amaterasu or Susanoo; it was mentioned that Madara's transplant took place after both he and his brother had unlocked the full potential of the sharingan and as such no similar loss of power happened there.
Does Itachi plan to somehow kill his already deceased best friend all over again in order to regain the mangekyo sharingan?