He is an operative in his mid-30's for the National Police Agency's Special Assault Team (SAT). Though he is fully human, he is as homicidal and apathetic to other people as the worst diclonius are. He is a hardy and effective soldier. After being maimed by Lucy and repaired with bionic, cybernetic and prosthetic implants, he escapes on a quest for revenge against her. He gets two or more Desert Eagle hand guns. In the manga he gets other weapons such as a RPG. The guns fire .50 caliber rounds which are so powerful the rounds can not be blocked with vectors. But the bullets can be pushed off course at long range though; however at close range not even Lucy can stop them.

Spoiler

He gets sidetracked several times in this quest, and ultimately receives aid from Kurama to "kill a diclonius that was coming." Bando is driven by the will to fight and to prove his superior ability in combat. At the end of the anime he is crippled again by Lucy while in the manga he is ripped in half, saving Mayu's life when Lucy tries to kill her. He is shown to have survived at the end, reuniting with Mayu.

(Source: Wikipedia)