He would've tried to capture Naruto by brainwashing him with Kotoamatsukami, but Kurama would resist so he isn't captured by Madara's forces and break through the Genjutu. Shisui himself would've probably been defeated by the Genjutsu immune Killer B and sealed.
Show me a manga scan of Killerbee being immune to genjutsu. KA controls the opponent without them even knowing that they're being controlled. It is one of the highest kinds of genjutsus we've seen so far.
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Even Itachi, knowing how strong sasuke's eyes are, and that they can break even his own Tsukuyomi, tried to use KA to control sasuke. This shows that Tsukuyomi, and not even Itachi or sasuke (two of the most powerful uchihas) can cancel this genjutsu.
Even Edo tensei which was shown to bound top class shinobi was no match for the genjutsu.
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And don't say crap about bijuu being capable of breaking through it. Obito's genjutsu captured the 3 tails jinchuuriki who was a kage. The mizukage then was one of the only jins known for controlling the bijuu. Obito had been shown to use his sharingan to control a tailed beast even inside the host
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Sasuke did not make plans before going to fight killer bee. He was hot headed and didn't have much info about jinchuurikis and bijuu. Obito knew very much about capturing bijuus. That was his sole mission at the time. If an uchiha intends to go at a jinchuuriki with intent to kill, not even the bijuu can save you from the genjutsu. Even naruto told Bee to stay clear of Itachi's Tsukuyomi because Itachi wasn't just any uchiha. Itachi was known more for his genjutsu than obito was. So not even having a bijuu would help you when you face him
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All I bring are manga facts, and you just say stuff without proof. Yes I am "obsessed" with the uchiha, they're the coolest fellows in the manga hands down and that's hard to deny. But I'm not dumb. I respect characters because of their swag and what makes them unique. Hashirama, Naruto, Gaara, Minato, Sakura . . . I like them for different reasons. But you're just a hater if you say stuff without solid proof.