Within the Marvel Comics universe, superheroes, technological geniuses, and mythical gods coexist, and as more comic characters transition into the Marvel Cinematic Universe, fans need to familiarize themselves with the diverse planes of existence. The finale of “Ironheart” finally introduced MCU fans to Mephisto. If you’re unsure why the lord of Hell is a canonical Marvel character, Looper’s explainer video above can assist you.

Mephisto has an extensive history in the Marvel universe, despite how peculiar it may appear. He first appeared in the third issue of “Silver Surfer,” engaging with almost every major Marvel hero since. Although he resembles Satan, Mephisto isn’t him, and his Hell isn’t synonymous with the Christian notion of Hell. Mephisto is a demon, which means he is immortal, possesses super strength and speed, and can manipulate reality as he pleases.

Speculation about Mephisto joining the MCU has circulated since “WandaVision” aired, but the demon made his debut at the end of “Ironheart.” In the first season’s finale, Mephisto (portrayed by Sacha Baron Cohen) strikes a deal with Riri Williams (played by Dominique Thorne) to resurrect her friend Natalie (Lyric Ross). Comic enthusiasts understand that this deal is likely to haunt Riri, and anyone invested in the MCU should brace for Mephisto’s significant influence on the universe moving forward.

Though it’s almost impossible to understand his true motives, Mephisto is always making deals with people, and just as we saw with The Hood (Anthony Ramos) and Riri in “Ironheart,” the demon can deliver seemingly impossible things. Hood learned the hard way that Mephisto’s deals can be too good to be true. In the comics, Peter Parker made a dark deal with the demon. In the “One More Day” storyline, Mephisto helped Peter make the entire world forget his secret identity, but in exchange, Peter’s entire relationship with Mary Jane was wiped from existence. 

Elements of the “One More Day” arc are present in “Spider-Man: No Way Home,” but Mephisto could still interact with Spidey in the future. The demon’s reality-shifting powers might also come into play in the next “Avengers” movie, because everything we know about “Avengers: Doomsday” leads us to believe it’ll be another multiverse-shattering adventure. 

Whatever his role in the MCU is going forward, Mephisto got a solid introduction in “Ironheart,” which has gone down well with critics. Riri’s deal with Mephisto at the end of the miniseries also perfectly sets up an arc for her and the demon lord of Hell in a potential second season. Mephisto’s powers could reshape any hero’s story, so if you want to be prepared for what he does next in the MCU, make sure to check out Looper’s video above recapping the character’s full history.