Remember Harley Keener, a.k.a. the kid from Iron Man 3 who also made an appearance in Avengers: Endgame? Well, he isn’t just Tony Stark’s one-time sidekick. He might just be one of the MCU’s newest heroes…and greatest villains. At least, according to a new fan theory. Join Dan Casey on Explainiac as he breaks down what you need to know about Iron Lad, Kang the Conqueror, and how this could all play out in the MCU.