I did it! I beat Isshin! Managed to counter his lightning three times in a row. Was almost dead with no room to heal, and no stamina to block. I was just about to back off to heal (which probably would have gotten me killed), when he suddenly did his stab attack. I caught it and that was the end of his posture! God I love this game!
Gratz dude. How hard would you say you found him as oposed to other bosses?
He was medium difficulty, but only because he was an upgraded Genchiro, and only because I had fought old Isshin before to get the Shura ending. There are sooooooo many opportunities to just dodge his attacks in phase 1 and cut him up from the back. When he does the slow three swing combo, you can dodge on the last swing. When he does his sweep attack you can dodge all the way around that. When he does double ichimonji you can dodge that too. His phase 2 was the hardest, because that spear has serious range, and his mortal draw attacks are almost impossible to predict whether or not they are sweeps or uppercuts. His phase 3 just needs you to catch lightning, and miriki counter his delayed stab attack.
Hardest boss in the game for me was Corrupted Monk the first time around. She blocks literally everything unless you get behind her, and her freaking mix up is insane. Her jumping downward slash looks identical to her jumping sweep. Honestly, without 5 confetti, and a chip damage approach, I don't see how anyone could beat her on the first try.