It seems fairly certain he was talking about her involvement in the artificial disciple experiments that created all those Fallen Ones -- we were also told somewhere around the same time that one of the Rouvelier family's duties had been to give up many of their own family members as experimental test subjects. I doubt Hevlaska directly killed anyone, but by willingly allowing herself to be used in the experiments, she became complicit. This seems to be why Malcolm hates her so much.

Ah yes, that makes much more sense. *nods, nods* And what you said about her having been "once human, and a member of the Rouvelier family -- namely, the "holy girl" they first offered up as a sacrifice to the Order." too. Yes, makes things much clearer, thank you. ^^