After years of teasing, Marvel has finally confirmed that one of its biggest villains is officially part of the Marvel Cinematic Universe, following the season finale of Ironheart.
Warning: This article contains major spoilers for Ironheart
Ironheart is a new miniseries featuring the character Riri Williams (Dominique Thorne), an incredibly talented MIT student who first appeared in 2022’s Black Panther: Wakanda Forever.
Much of the series involves Williams’s dealings with Anthony Ramos’s enigmatic Parker Robbins, also known as “The Hood”, after she discovers plans pitting the world of magic against technology.
When Williams manages to defeat Robbins, she is then confronted by a stranger, portrayed by Sacha Baron Cohen, who reveals himself to be the MCU’s devil incarnate, aka Mephisto. After mistaking him for another MCU villain, Dormammu, Williams is corrected by Mephisto. He then manipulates the hero by offering to resurrect her deceased friend, Natalie, who has been turned into artificial intelligence.
The episode ends with Williams being greeted with a now-living Natalie. However, she appears to have been corrupted by Mephisto, with disturbing black veins now visible on her skin.
“The devil is in the details,” wrote Baron Cohen in an Instagram post after the episode was made available on Disney+.
The debut of Mephisto is the MCU is one that fans have awaited for years, as the character has been teased in numerous TV shows such as WandaVision, Loki and Agatha All Along.
Understandably, fans were ecstatic to finally see the character on screen. “MEPHISTO IS FINALLY HERE! THIS IS NOT A DRILL! 4 years of waiting finally paid off, I never thought this day would come,” wrote one excited fan.
“That ending for episode 6 had me floored! Riri Williams making that deal with Mephisto to bring Natalie back was insane!” exclaimed another.
Others praised Cohen’s performance, calling it “spine-chilling” and “amazing”.
Elsewhere, eagle-eyed viewers spotted that there was a small Easter egg that showed Mephisto in his traditional “devil” appearance, with his face shown as demonic red in the reflection of a spoon.
“I was so busy losing my mind that I completely missed Mephisto’s reflection in the spoon oh my god,” remarked a shocked viewer.
“Mephisto from the reflection of the spoon looks so freaking awesome even from this angle,” said another fan.

Mephisto, who is based on the character Mephistopheles from the Faust legend, first debuted in Marvel comics in 1963 and has been a recurring enemy for numerous heroes including Silver Surfer, Ghost Rider, Doctor Strange and Spider-Man.
At this stage it remains to be seen what will happen next with Mephisto. The character is yet to be confirmed for any future Marvel projects, although he does play a prominent role in the Secret Wars comic series, which is being adapted into a film due for release in 2027.