As with all Zodiac mutants, it cannot be bred and is unable to upgrade with Stars.
Geminium its a mutant composed of two sides, one side is made of diamond with a hammer as a hand, and the other side is dark with spikes and a big claw for hand. Its Geminis symbol is located on the right side of its chest. It looks as if one side is trying to overcome the other as shown by the mutant's ever changing torso and head from light to dark and back. The Light side takes complete control of Geminium when executing its Ego attack, in which it uses two diamond hammer hands to launch a barrage of punches. The Dark side takes control when using its Alter attack, in which it floats into the air and raises its hands to generate a ball of dark energy which shoots beams.
- Attack: Cataclysmal
- Life: Tank
- Speed: Slow
From the Gemini star sign, two shooting stars were seen to crash into each other before impacting in the desert near the arena. When sent to investigate scientists found an unusual sight awaiting them, The mysterious Geminium was discovered. Two mutants merged into one, it is no surprise that Gemimium has chosen to join the arena!
- Geminium's light side resembles Diamondhead from Ben 10.
- Geminium's dark side and storyline is reminiscent to the symbiote, Venom, from Marvel Comics.
- The dark side of Geminum could be a reference Extroyer to the animated series Max steel.
- If you combine the name of his second attack and first attack, you will get "Alter Ego" which fit his character.