Doomsday theory explains how Robert Downey Jr.'s Doctor Doom can save the world, becoming the hero of his story, like Thanos did.

From Time Runs Out to Namor and Sue Storm's relationship to Emperor Doom, Marvel's Avengers: Doomsday tease hints at a huge swatch of comics history.

Kelsey Grammer’s surprise return as Beast in The Marvels post-credits scene left many scratching their heads. His sudden reappearance as Dr. Hank McCoy, blue and shaggy, welcoming Monica Rambeau to a parallel universe seemed like an odd outlier, especially since the character hadn’t been seen for years.