Master of Attraction Flies Alone

Master of Magnetism does not concern himself with allies.

Why bother, when he can use In Harm's Way to deal 6-7 damage and remove just as much threat, then safely flip to alter-ego and shuffle that card back into his deck, possibly alongside his signature resource, to repeat that effect multiple times within the same deck cycle?

The Best Offense works very well alongside readies from Magneto's Cape, not to mention Army of One and Ever Vigilant, and an occasional boost to defense from Magneto's Armor certainly will be appreciated.

It really is a straightforward deck, just make sure your regular, non-boosted basic actions are strategically spent on removing threat from the main scheme, so you can flip to AE in case too many of your DEF upgrades get discarded from Magnetic Pull. Once built up (not even fully, some pieces are optional), the damage output will be high enough to compensate for slower early game.

Magneto's Helmet is very skippable (unless the scenario is status card-heavy), The X-Jet and Deft Focus should be prioritised over it. Magneto's signature Armor can be useful, but will whiff every once and then, so the DEF upgrades are preferable if you have to choose between the two. As such, once you get the Cape on the table, Superpower Training should be played only if your companions need it.