Sebille has escaped from slavery, where she was forced to hunt down and kill fellow elves. That wasn’t exactly done willingly; her ‘master’ had put a controlling sigil on Sebille’s cheek. Now free from both, she’s obviously quite keen on getting some vengeance. The elves in Divinity: Original Sin 2 sometimes engage in cannibalism, so, you know, that might be involved.
The game will be out on PC later this week, on 14 September. Final build codes haven’t been distributed yet, so keep that in mind if you see any release day reviews.