X-Ray is a member of the U-Foes, a villainous group with origins tied to the original Fantastic Four. They tried their best to be bombarded with cosmic rays, and succeeded in getting more than the FF had. He is made out to be the Human Torch of the group, but it is worth noting that their powers are vastly different, and X-Ray has a master’s degree in engineering, which I think is far above the education of Johnny Storm.
X-Ray has control over radiation. He cannot turn his body into its normal form, but is instead is a living energy field of radiation. He can transform, emit, and absorb all sorts of types of radiation, and is intangible and invisible at will. However, it appears that some things, such as lead, or Thor’s hammer, can still harm him in this state.
He has battled Hulk and Thor alongside his team, but always come up short. However, more recently the U-Foes registered as super heroes with the government and helped Osborn when he was in charge of SHIELD (which he renamed HAMMER). They attacked Volstagg, an Asgardian which resulted in a devastating catastrophe and was the catalyst for the Marvel event Siege. Since then, I have not been sure what they are up to, but I would guess they are still lurking around somewhere.