[Shujin]

Pretty much this, it does too much for too little. I made a joke build with it on a dullahan super tank stun regen memes. It beats most builds effortlessly by just spamming that (barring high dark res people.)

4 turn cursed wound is also darn long, for how easy it is to use. So what I think could tune it down a bit:

-As spo says increase it's rage needed and adjust its power a little upwards, but let it go against Mag. defense
-Reduce the Cursed wound duration. 2 Rounds is fair enough for it. Maybe 3 if its less spamable.
-make it a knockback 1 tile while on ground. Also prevents double tapping in many cases and gives you some breathing room.