I'd say magic makes more sense, though it's your call whether the armor and sword of storms are a one off mystical artifact (norse, or Japanese, perhaps?  I could see Raiden making such a thing) or a Frost Giant artifact sized for a normal human, as part of an experiment initiated by Ragnarok to create enhanced super soldiers.<br/><br/>I suppose it could be some kind of electromagnetic device using Tesla technology, but we already do have a technological character, so someone with magical expertise could be handy.