A demon once summoned by Amanda Sefton while she and Storm were members of a powerful coven of witches. Magnus wiped out the witches, but before he could finish off the one who summoned him, Amanda and Storm managed to banish him to the electromagnetic spectrum, where he was held captive by the stronger magnetic forces of the planet. Afterwards, they invited to join the X-Men and Storm accepted, while Amanda instead turned to crime, believing her magic made her above humans and mutants.
When Rogue joined the X-Men, she was approached by Magnus who hungered for a new body. Taking advantage of her insecurities, Magnus convinced Rogue to aide him. Going to see Amanda, the witch agreed to help with the intention of killing Magnus.
Sealing him into the body of Colossus, she set about trying to defeat him, but using his ability to control metal. Magnus impaled her. Battling the X-Men, Magnus had the upper hand until Rogue, having absorbed Jean Grey's powers, defeated him, forcing him out of Colossus' body.
Powers and Abilities
While he longs for a body, Magnus can be permanently killed whilst in a physical form.