Tuma is the former leader of the Skrall in the Shattered Mirror Universe. Following his defeat, he became a mercenary, leading a team made up of Stronius, Metus, Fero, Branar, and several other Skrall.
Tuma led the Skrall species on the Shattered Mirror Universe's Bara Magna up until OU Blackout came and conquered the planet. Blackout deposed Tuma, becoming the new leader of the Skrall, but chose to spare his life. Though Tuma no longer had control over the destinies of his people, he still had enough influence to recruit some rogue Skrall, including Branar and Stronius, to his side. Tuma decided that because he was not powerful enough to defeat Blackout, he would make a living by doing freelance mercenary work instead. He formed the Skrall who followed him into a team, which also came to include Metus and Fero, an Agori and a Bone Hunter respectively, who were allies of the Skrall in the time before Blackout's arrival.
Upon nearing his target's location, Tuma's ship was attacked by Crona, causing him to fall out and into the cathedral where his targets were. Then Zev Raregroove used some sort of mirror to remind him of how he masterminded the extermination of the Skrall, and then started beating him up while moving too fast to even be seen. D-Klak tried to help Zev, but Nadle stopped him.
After these events, Tuma fled back to the Shattered Mirror Universe, which is where he remained until he was recruited by SM Trantoshen to participate in the invasion through the Shattered Mirror II. In the ensuing battle, Tuma killed several attendees of Kakamu's funeral. After chopping a woman's arm off and crushing her beneath his feet, a male human leaped onto Tuma's back, removed two of his four back-mounted swords, and crossed them across his neck, warning him that he would kill him if he did not surrender. In response to this, Tuma commanded the other two blades to spin around and kill the man.
SM Tuma's current status is unknown, but if he was still on the battlefield when Weapon X was activated, he was disintegrated and killed.