[Miller]

I'd rather just give Sayakensa a potential skill. Something like, say, a passive that adds Dark ATK onto your Sword/Katana attacks/skills but hits you with a significant Cursed Wounds that builds up each round and can't be cured.

I can get behind this as well.

50% Darkness attack on hit/Kensei skill with half of the inflicted dark damage being equal to the LV of the self-inflicted cursed wounds.