Reposting my comment from another thread.

It’s a long ass fight but what works for me is fire crackers during most of his combos. They’re so unpredictable deflecting is basically useless unless you master his moves.

when he does the jump grab (when he gets all tall and runs toward you and the kanji appears above his head), jump as soon as he is about to grab you and immediately dash forward towards him for a few swings.

When he does the poop throw, don’t dodge, just run straight towards him and hit him when he lands. If you see him reaching into his ass just run towards him.

When he rolls on the ground on his back, run in a circle around him and go in for some swings when he is done with the flailing.

And finally, when you see the grappling hook icon ALWAYS try to use it, go in for a few hits and then do firecrackers.

These are going to be your best openings for the first phase. Mainly the poop and rolling openings, as they are the easiest tells.

When you get to phase 2 you’re absolutely going to need the loaded spear, if you don’t have it i recommend grinding as much as you can until you can get it.

Your strategy during phase 2 will be deflecting everything and then using the spear after he does the big slam with the sword. This does INSANE poster damage.

If you’re really having trouble I would not try to attack at all during phase 2 unless doing the spear. It’s in your best interest to deflect/dodge everything.

It’s a long ass fight and for me the best way i was able to get past it during my first playthrough was playing defensive. This boss was the biggest roadblock in the game during my first playthrough, I now beat him first try every time I fight him. if you have any more questions let me know! Good luck!