as for that shisui theory
itachi told him personally, that he did it killed him as his wish
we dont really know if shisui was the reason that his MS came out. i don't even recall him saying "i killed shisui" rather, you must kill your closest friend to get the MS

itachi coulda got MS from a variety of places.
how about the struggles with killing your family?
How about the mixxed feelings about the mission?
you don't need to kill yoru closest friend to get MS, you simply have to feel immense emotional trama.
for sasuke, it was realizing that he killed the one person who was defending him this whole time, and even defended him, when he was trying to kill him.

I don't get why everyone started talking about hidan

hes buried in that nara clans forest that only people of the nara clan are allowed to enter or leave. kabuto probably couldnt get in there and take hidans dna

possibly

He probably didn't know about it at all.

I said Hidan was immortal, why can't the Sage or the son of the sage be?

hidan is weak

hidan prob still alive lol

his skill, to inflict whatever damage or technique on whoever's blood he tastes


it will be the perfect anti-seal

cant get sealed if he keeps blood on his technique

He's still very slow. Out of 10,000 he can only harm one if he's reassurected.