Rayner is an experimental super-soldier, genetically created and grown in a laboratory hidden deep in the jungle. During his childhood he was experimented on constantly, undergoing daily tests he was subjected to by the scientist.

Whether it was something to do with the experiments, his genetics, or just the fact he was becoming a teenager, Rayner began to become very aggressive to the scientists. He started to refuse cooperation and even physically assault anyone who entered his 'enclosure'. It became increasingly difficult to safely work with him, to the point most procedures didn't go ahead unless Rayner was heavily sedated.