It doesn't do any damage. But the wraiths from the Omen Bairns do holy damage.

WTF? what does the omen bairn doing holy damage have to do with this sword?

Because the Dung Eater uses the Omen Bairns, as well as this sword

25 Jul went crazy, I guess

For the debuff portion, yes. That remains for its full duration regardless of what you do unless the enemy in question dies. The buff portion remains if you change two-handing states, but doesn't take effect on other weapons. It goes away if you swap this out of either slot, though.

would be cool af ngl