Marvel fans outraged as fan-favorite villain is 'wasted' after finally being revealed in new MCU show

Marvel fans have been sharing their frustration online after an iconic villain, one they had been waiting for, was finally given a long-overdue introduction.

With all the hype around the movies, especially for the upcoming Avengers: Doomsday, it's easy to forget about Marvel's plethora of TV shows.

And the newest addition to the lineup, Ironheart, had its season finale last night on Disney+. The show follows Riri Williams (Dominique Thorne), an exceptionally talented MIT student, as she navigates the intersection of the technical and magical worlds, as well as dealing with Parker Robbin's 'The Hood' (Anthony Ramos).

This isn't William's first appearance as she'd made her debut in Black Panther: Wakanda Forever, where she gets her own Iron Man-esque suit.

But Ironheart is her standalone show, and the finale introduced a very special villain to the MCU universe.

Warning: spoilers for Ironheart ahead.

Ironheart's season one finale aired last night (Disney+)

Fans finally got to see the long-awaited Mephisto in the season one finale of Ironheart, played by Borat star Sacha Baron Cohen.

In the show, it's revealed that he'd offered Robbins, a cape which is powered by dark magic. Mephisto then appears to make him a difficult offer, saying he could be richer and more successful than his estranged father, according to Polygon.

But like any good villain, there's more than meets the eye to the offer and a definite sting in the tail: Peter can never go without the cape.

He also later appears to Williams and offers to resurrect her friend, Natalie - only now she is controlled by Mephisto.

After the episode's debut, Baron Cohen later wrote on Instagram: "The devil is in the details."

However, some fans were disappointed with his appearance, as one person said on Twitter: "A reveal wasted on a lackluster show."

"Why did it have to be Ironheart? Underwhelming after so long." wrote another.

Sacha Baron Cohen appears as Mephisto (Disney+)

Meanwhile, others wished he'd appeared in other shows, like Agatha All Along or Wandavision.

However, some were delighted by Mephisto's reveal, with one viewer writing: "MEPHISTO IS FINALLY HERE! THIS IS NOT A DRILL! 4 years of waiting finally paid off, I never thought this day would come."

Another said the ending had them 'floored', adding: "Riri Williams making that deal with Mephisto to bring Natalie back was insane!"

A third praised Baron Cohen's performance, calling it 'very charming, controlled, mysterious, and creepy', while a fourth said: "Mephisto’s introduction feels as big as He Who Remains introduction at the end of Loki S1 and that really excites me for the future of the MCU."

There are many new Marvel projects on the cards, so this probably won't be the last we see of him.