I’m working on my first playthrough of Sekiro right now but I’m kinda stuck. Corrupted Monk just takes so little damage from my attacks I’m not sure if I’m doing something wrong.
I haven't played for years, but from what I remember, the posture damage is shit. There are moments where the Corrupted Monk is open after an attack I think. This is the moment to strike.
Edit: it took me back haha, but there are those big attacks where you have a red symbol over your head, you dodge that attack and strike.
Corrupted monk has a lot of health. It helps to use Divine Confetti and maybe Akos Sugar. I rarely deal enough posture damage on him without depleting his health bar.
Be aware snap seeds are a limited resource until after the >!True Corrupted Monk!< fight, which is both optional/missable and also exists near the very end of the game.
You can allegedly farm them off some monkeys in Sunken Valley but you're going to be spending an awful lot of time there for minimal returns, the drop rate sucks.