He didn't even die there, if you can believe it. Though he is catatonic and carried home by Jean Grey. This is one of the few comic books I actually had.

Immediately after this, Xavier gets pissed and completely mind-wipes Erik, something he promised he'd never do. This causes a part of his psyche to splinter off, eventually kidnap Franklin Richards, and merge with him to become Onslaught.

Then an amnesiac, de-aged Magneto shows up to help the X-Men fight Onslaught.

Comics are wild, man.

The adimantium was actually poisoning him, and his healing factor was fighting it the whole time. So when he lost the metal he became ultra powerful and developed bone claws

I've read comics where wolverine has been dismembered in half and still lives through it.

He survived having molten adamantium injected onto his bones. I'd guess that this wouldn't be as bad as that was.

There's only one substance more powerful than adamantium in Marvel comics: popularity-induced plot armour.

Magnetic fields, which is part of electromagnetism. He can directly influence one of the fundamental forces of the universe. Magneto is definitely one of the strongest mutants.

If he'd learn to do things besides bend and move metal, he'd be able to do almost anything depending on how acutely strong of a field he could make. With how field lines snap in the sun and make for huge discharges of charged particles, I think Magneto would be able to do a lot even without making hugely powerful fields if he'd learn some science.

Controlling magnetic fields he couldn't physically move non ferrous metals, but he could sure cause a lot of energy to be dumped in due to induction. Essentially cooking wolverine, and then melting his adamantium into a pile instead of being bone/blade shaped

Edit: yep spoke before I thought... and learned something new about frogs lol. Non ferrous are just not attracted to magnetic fields.