Found her bio description, suprised to see that site is still existing.
Yllia is a half-Mazoku, created by Xelloss through the fusion of a human shell and a low-level Mazoku. Because of this, she possesses a much higher magical capacity than normal humans, enough for her to be able to use a form of teleportation magic that is very costly (in magical energy).
Her weapon of choice is a black rapier-whip, a blade of long slender metal that can be wielded as a whip. She only grudgingly obeys Xelloss, because she knows things could be a lot worse if she disobeys him, and hates him fiercely.
She and Val get along splendidly, not exactly a copy of their 'parents' relationship but close.