Kamishiro Yomi

Was given the name "Val" by Lilith, and inducted as a member of Valkyrie (Death Reapers of the Battlefield) after her "death". However Yomi's death was prevented after Lilith gave Yomi a gems containing her life force; Thus Yomi considers Lilith to be her master for saving her.

And yet, ends up forsaking the gem and attempts to kill Lilith regardless.