The last survivors of Planet L77, the Leo Brothers were trained as assassins at a young age. When their planet was destroyed during their childhood, they found a place with the Star Cluster Alliance. Though some members of the council felt that the brothers were too uncontrollable, they performed their job as hitmen for many years.
The Leo Brothers made their first appearance on Earth upon being summoned by the Star Cluster Alliance. They were sent to kill Agent Adad as well as the illegal aliens he was sheltering. The brothers tracked down their target and engaged him in combat, managing to overpower the agent at first. However, Adad took a pill and transformed into a massive, hulking version of himself. Adad's increased power forced the brothers to revert to their true forms, where they managed to injure their target. Despite this, Adad's friend Sam rushed to his defense and attempted to shoot Astra.
Before the brothers could kill Sam, Dan Moroboshi appeared with Windom. Angered, Astra charged Windom, but was shot down and incapacitated by the robot. Adad regenerated from his injuries as Leo and Moroboshi traded threats, preparing to battle.
- Powers and Weapons
- Super Human Physicality: In their human forms the brothers are able to compete with Adad, whose strength is approximate to Moroboshi's when he wears his Ultra Suit. In their true forms, they are able to overpower Adad easily
- Short-Range Teleporters: The Leo Brothers use short-range teleporters to give the appearance of rapid movement.
- Transformation: The Leo Brothers are capable of a limited form of shapeshifting, giving them an almost-human appearance. When they shed this disguise, their combat ability goes up.
- Unlike their inspirations, the Leo Brothers in the manga are villainous with more similarities to the Alien Magma than the Ultras.
- Leo and Astra have what appears to be a bracelet.
- Their armors also contain small-shaped holes in the upper chest armor based upon their counterparts. (circular for Leo and rectangular for Astra respectively)
- The Leo Brothers relationship with Dan comes into mind the mentor-student relationship of Dan and Gen.