I have DE and just noticed this debuff on Red Prince. I only noticed it upon entering the Academy, so I'm not sure where he got it from, but I did just fight everyone at Temple of Tir-Cendelius, including the Lost Knight, fwiw. I managed to get rid of it by having Lohse drop him in lava then moved his corpse back to a safe location and resurrected. But I'm sure that's not how things are supposed to work. Could be a mod, but, not sure.
