Avengers: Doomsday teaser brings Fox-era X-Men into the MCU, with Xavier’s school, Magneto voiceover, and Cyclops blast setting Doom stakes.

Magneto has stood the test of time as one of Marvel's greatest creations because he's as flawed and tragic and compelling as any other Marvel character, hero or villain. You may not support his methods, but you darn well understand why he does what he does.

Magneto, Doctor Doom, even Thanos, are all extremely dangerous villains, but the most dangerous Marvel villain is actually Mister Sinister.