Selene is needing for out Infinity Gem plot.
Selene has been searching for the gems and a way to use them to give herself an unlimited source of power. She found one the same time Kevin Ford and his Dad did and battled for it. Selene came out the winner and ended up taking Kevin captive after his Father died due to his powers and their ability to touch the gem. She is now Kevin's former Mystical Arts Master and Ex-Girlfriend and is hunting him since he stole the gem from her.
If she actually cared for Kevin or just wanted him for his use to her if up to you.
Playby: Preference is Jenna Dewan Tatum, but it can be changed.