The twin red skinned cosmic mercenaries known as the Blood Brothers are incredibly powerful and ruthless. Their powers increase when they are in close proximity of one another. The farther apart they are the weaker they become. They first became known as henchman for the Mad Titan Thanos. They were the guardians of his secrete base on Earth. They have taken on Earth heroes such as Iron Man, Daredevil and the Avengers while they were on Earth. They have also battled the cosmic heroes known as Starfox and Drax the Destroyer.
The Blood Brothers were imprisoned in the Vault after their battle with the Avengers. Quasar for some unknown reason convinced the Warden to release them into his custody so that they could participate in a battle arena. He takes them to Mars where the Brothers pound unmercifully on Quasar, until Wonder Man contacts him to inform him that Makkari is on the move. Quasar uses the power of the quantum bands to form to giant hands, which he uses to help him, escape. The Blood Brothers are left stranded on Mars.
They managed to escape their exile and one of the brothers appeared in a bar on Earth where he fought the U.S.Agent. The Agent easily defeated the one brother. After that it was learned that the Living Planet Ego was about to attack the Earth. The U.S.Agent enlisted the Blood Brothers and a bunch of other aliens to help him battle Ego and an enhanced race of Kree known as the Ruul. Together with the help of the heroes of Earth the Blood Brothers were able to help save the planet.
This act of heroism in no way means that these two cosmic bad boys are in the hero business. They are later found on a prison transport vessel in route to the Kyln prison station located at the Universal Crunch. The other inmates on the ship are Drax the Destroyer, Lunatik and Paibok the Power Skrull. The transport crashed on Earth near a small town in Alaska. All the inmates survived the crash and were discovered by a ten year old girl by the name of Cammi. The Blood Brother became engaged in a battle with Drax the Destroyer. The battled ended with one of the Brothers losing his life. It is unclear if the surviving brother became weaker or stronger as a result of his brother’s death. It is safe to say that time will soon reveal this answer.