Sorry I forgot a bit of background, here it is:

He doesn't know (anymore) where he comes from, who his parents are, etc. At the age of ten he was found on the stairs leading to the rooms of the pope in the Vatican. No one knows how he got there. No one even found out anything about his past, all they actually did found out were some weird lines Gorrath kept repeating:"Noooo, don't let it strangle my face again! I'll choke, it hurts too much!". He was trained to exterminate evil ever since by a society founded by the leaders of every single religion in the world. The real story about his past is this: he was the son of a powerful sorcerer that once protected mankind at the side of the Legendary Dark Knight himself. He was kidnapped by extraterrestrials and was used for an experiment. The aliens wanted to use him as a host for the last Xenomorph-facehugger in the universe. This one had also Predator-DNA in his veins. The experiment failed. The embryo of the chestburster died and its DNA combined with Gorrath's for a last chance of survival. The aliens were very angry. They returned to earth and dropped him right on the stairs where he was found. During his training, Gorrath learned to control his powers and also gained control over his extraterrestrial instincts.