Not much is known about Ricky's early life. He is introduced as a mutant outcast under threat from homo-sapiens in his neighborhood after his destructive powers were revealed. Ricky was saved by Magneto and Xavier, just in time to avoid being killed by neighbors and people he thought were his friends.
He was next seen in the Savage Land with Magneto talking about the use of his real name as opposed to his codename. He believed "Detonator," sounded weird, but Magneto proclaimed that his real name should be forgotten, since normal humans gave him that name. When Xavier convinced some mutants to leave the Savage Land, Detonator decided to stay with Magneto. He later appeared in the Pentagon and killed several workers with his explosions.
Ricky would meet his end during the events of Ultimatum. He died in the service of Magneto.
He seems to be able to create powerful explosions. He could throw a punch, and upon contact, start an explosion, making quick work of jail cells or enemies. He could tear through walls, cause a maximum of damage to any structure with a minimum of effort on his part. The extents of his power were never developed. Therefore it is unknown if he spontaneously combusted his own body parts, then reformed said body parts (see Breakdown), or if he simply created these explosions around his person, yet had a natural immunity to this power like so many mutants do.