Kalus

Kalus is one of the main antagonists of the video-game "Kameo" and was also the sister of the titular hero.

Kalus was driven insane by jealousy and sought power for herself by awakening Thorn, the Troll King, she also unleashed her own magic to capture many of her own family and imprison them while also stealing her sister's elemental sprites so as to leave her powerless.

Despite her madness it was later revealed that Kalus was in reality a pawn to The Mystic and upon realising how she was being played for a fool sought redemption by facing Thorn, only to be overpowered by the powerful troll.