Maxima hails from the planet Almerac, and is considered royalty there. She was sentenced to Fort Rozz under unknown circumstances. When the fort crashed on Earth, Maxima sought out Superman and tried to convince him to become her mate. The DEO imprisoned her, and Non later freed her in return for her subservience.
Maxima has near-Kryptonian strength and endurance, enough to go head-to-head against Supergirl. She may use mental abilities to augment her body.