The poster child for swapping sides, Magneto’s sympathetic motivations – his actions are fuelled by his horrific experiences at Auschwitz – have led to him teaming up with the X-Men numerous times. Indeed, the Master of Magnetism and X-Men founder Charles Xavier were once BFFs, who bonded over their
mutual desire to ensure the survival of the mutant subspecies.
Magneto and Xavier famously fell out over the former’s more militant, less inclusive stance on mutant rights, but both remain champions for mutant rights. As such, Magneto has never been afraid to lend Xavier’s students a hand when their immediate goals align with his, and he’s even officially joined the team on occasion (although he tends to split before too long).