Ridley (Metroid)
Often considered one of the most memorable Nintendo villains, Ridley has been a mainstay of the series, having appeared (through various incarnations) in almost every "Metroid" game to date (all but "", "Metroid Prime Hunters" and ""). He has also appeared in the "Super Smash Bros." series, however, he had not been made a playable character until "Super Smash Bros. Ultimate" in 2018, making it also the first game overall to have Ridley as a playable character.
Superman/Wonder Woman
In September 2013, DC revealed that Doomsday and General Zod would be among the first villains introduced into the series. Soule said, "We wanted to go big off the bat. We wanted to stake our claim and make it clear that this was a book that mattered — not just from the idea of the couple at its heart, but also from the events that would be depicted in it and their impact on the DCU as a whole, and in Superman's life and Wonder Woman's life."