How Franklin Richards, the power cosmic and Doctor Doom's appearance in "The Fantastic Four: First Steps" credit scene affects "Avengers: Doomsday."

As Fantastic Four: First Steps heads towards its final act, the group is torn between two impossible choices: sacrifice all of Earth to Galactus, or Reed and Sue must give up their child Franklin, who contains the Power Cosmic and enough energy to satiate Galactus' hunger.

In a 1982 arc by John Byrne, Franklin gets frustrated trying to solve a Rubik’s Cube and uses his powers to age himself into an adult body, though he couldn’t actually gain more emotional maturity. He winds up going back to being a kid, placing restrictions on his own abilities to allow him to have something of a normal childhood.