Demonic Alien. Adversary of Fusionator. Her Race is known as the Sarkrel.

Tesa Kavush is an alien of the race known as the Sarkrel.
Her brother was dying and she had calculated a Cosmic burst that would interact with a comet and produce an effect that would empower her brother and save his life. Instead That power was absorbed by a Human astronaut Charlie Cooper.
Her brother Tavax died.