A death battle is a win to resonators decide to see whose character is stronger they go to neutral ground into the Colosseum, and they are able to then summon there, Comic book characters to test their might in the arena, comic book characters can only use the power and knowledge that is gained through the reading of their books Their levels also can only be raised by the books the resonator put into them during the battle
In character death battle
An in-character death battle is when a resonator fuses with his partner, the resonator continues that character's power as if it is his own to fight in the way that he would if he had the power for himself. Once this happens, there is no requirement of adding scans to raise power, because all the knowledge is downloaded through the books directly in the resonator