Hkj
A Madara on the verge of death to fight someone like yamamoto seems very illogical to me, even madara being at his best could not do anything
HOS:So what's the connection of it? Being head captain is just a position, just the fact rukia became one does not mean she's the strongest shinigami. Bankai is still the biggest power boost of his powers and the mc does not have access on it yet. Also SHIKAI Yamamoto while strong is not particularly special in TYBW arc. Bankai yama on the other hand makes him practically invincible on Naruto verse.
I'll drop this if somehow Madara or black zetsu suddenly acquired kagutsuchi's cell! the flames around him should've burned all DNA flying in the air during their fight. don't do stupid things, I'm sure you nerfing Yamamoto's power already annoyed some of your readers so don't push us into dropping your amazing fanfic.