Look, all that anger has to get out somewhere, and his fists aren't big enough for that.

He's not big enough or strong enough, especially with Hastur not giving a single shit if he gets his face punched off, so he can't afford to eat too many hits here. Fist to the gut was barely avoided, though the rattling scuff to his ribcage started up a series of barking coughs.

Don't worry though.

The immediate attempt to headbutt Sanzo in the face and break his nose makes up for the moment of weakness.