@mage_goo
Nope, he called her his slave and "subservient sow" just after she woke up in the inn with no memories (he also used some kind of incense to hypnotize her into believing that, iiuc). So both she and Setsuna are his slaves, although he is acting rather nicely around them (yet?) considering his real edginess.
@siscon
Well, she didn't play part in original timeline, but Setsuna seems pretty normal for a revenge driven character.