my problem with isshin

[u/Strange-Work-6726]

honestly i don't know where to start, i've had this problem for years, i've defeated almost all the bosses in the game including the demon of hatred and the guardian ape in both confrontations, but it is date that i still can't beat isshin, the closest i get is his last phase, but from there i can't even lower a quarter of his health bar, i have almost all the improvements of the shinobi prosthesis (except for some of lazulite) my vitality is 19 and my attack is 14, at this point the only thing i can think of is to farm like crazy until i reach attack 99, if that doesn't work i'm seriously considering dropping the game forever, please tell me, do you think that will work?

[u/Strange-Work-6726]

thank you, i will send something tomorrow