He originally joined the Black Order five years before the storyline to pay for his daughter's medical fees. After being sent on a mission to find General Zokalo, his teammates Chaker Rabon and Kazanna Reed are killed by Tyki Mikk. Their deaths frighten Suman, who does not want to die. After giving away the locations of his comrades in exchange for his life, Suman is judged by his Innocence and becomes a Fallen One (咎落ち ,Togaochi), causing the Innocence to constantly deteriorate his body. Allen attempts to remove the Innocence from Suman's body, but succeeds too late. This results in the death of Suman's mind. However, his body is destroyed by the Teez Tyki Mikk had implanted in his body earlier, in exchange for not killing him before. He has a parasite-type anti-akuma weapon, which takes the form of a gem-like stone near his thumb. It is currently in the possession of the Black Order.

(Taken from Wikipedia)