Alidar Jarok wrote:
You're seriously questioning the science of a Marvel superpower origin story? It's clearly a world where gamma radiation, cosmic rays, etc. cause superpowers. Radiation has always given superpowers in this universe. It's clearly just building on that folklore.
Actually the MCU version of the Hulk got his powers from an attempt to recreate the Erskine supersoldier formula, though gamma irradiation was part of the process (presumably taking the place of Erskine's "vita-rays").
So maybe there was some other factor that Chan was exposed to along with the radiation. The episode was deliberately ambiguous about the source of his powers.