Childhood: Born a Saiyan mutant, Maiz has exceptional abilities. These consist of: Basic Saiyan traits (Strength, speed, senses, etc), a healing factor strong enough to regenerate his whole body as long as his head is intact, telekinesis, higher than Broly level potential, high level perception, and that's it. As a kid, he went to earth and was raised like a human but was aware of his Saiyan lineage. Unlocking Super Saiyan at the age of 7, he fought for the good of people until he was an adult. He met his brothers Spri and Charge at around 18. Adult Years: Training more, he unlocked a multitude of forms, (SSJ2, 3, Crystaline Ruby, Crystaline Ruby Evolved, True Rage), He got married at around 23 years old but it was short lived, the universe in which he stayed was destroyed in a godly level explosion. Nothing was left of Maiz but a head, floating around in nothing. When he regenerated, his lungs adapted, no longer needing oxygen to survive. With his family dead and nothing left to do but travel, he jumped to another universe. His friends that he made in the previous universe had ended up surviving the blast by escaping. It was bad luck that his family had ended up dying though. Current: 27 with a strong will to fight and the lust for revenge, Maiz keeps moving through his life. Faking smiles and focusing on strength and the advancement of his friends. After unlocking True Rage Evolution, he dedicated his life to absolute strength. He used his ridiculous speed to hop through dimensions and fixed them with his absolute power. It wasn't all great though, evil brewed within Maiz's soul and it was only a matter of time before he turned on even his own morals...
I'll try to keep it as concise as possible.