Nightcrawler is one of the most iconic of the X-Men, a notable hero in the history of the franchise, and one of their best visual representations of the core message of the franchise. But in the world of Earth X, Nightcrawler was targeted by Mephisto and transformed into a truly terrifying (and familiar) form.
The Earth X reality radically reinvented various heroes and villains of the Marvel Universe. But perhaps none were as transformed as the Nightcrawler of this world, who on top of losing his powers was quickly targeted by Mephisto and turned into that world's version of Belasco -- the demonic lord of Limbo who had once kidnapped Illyana Rasputin and fought against the X-Men.
Earth-9997 -- the reality of Earth X and the subsequent series by Jim Krueger, Alex Ross, John Paul Leon, Bill Reinhold, and Todd Klein -- initially began in a similar way as the core-Marvel Universe of Earth-616. However, things quickly took a turn when a series of events and tragdies radically altered the future of the entire world. In this world, Nightcrawler and his teammates on Excalibur (Captain Britain, Meggan, Black Knight, and Spitfire) were confronted by Grey Gargoyle. Most of the team was turned to stone by the villain -- with Nightcrawler only surviving thanks to his teleportation. However, he lost an arm in the process. Captain Britain then flew into a rage and slew Grey Gargoyle, leaving his friends trapped in their new form as he became the new King of Britain.
In that instant of Kurt's teleportation though, the Terrigen Mists were unleashed upon the populace -- giving almost everyone on Earth superpowers. Ironically, Nightcrawler appeared without his distinct blue fur and tail -- but in a world where such a visage would have allowed him to blend in. Instead, he was beaten and left for dead by a local village. He was approached by the devilish Mephisto of this reality, who gave the embittered Nightcrawler a chance for revenge against the world and convinced him that even his loved ones had only ever seen him as the monster he appeared to be. Nightcrawler was whisked away to the hellish dimension known as Limbo. With his powers, Mephisto transformed Nightcrawler's appearance and clouded his mind with false memories.
All together, this turned Nightcrawler into the spitting image of the X-Men's former devilish enemy Belasco -- seemingly revealing the Earth X incarnation of the demon was in fact Nightcrawler all along, thanks in part to a time-loop set into effect by Captain America refusing a deal with Mephisto. His frequent targeting of the X-Men over the years was even hinted to be a subconscious cry for help towards his former allies. A confrontation with the resurrected Mar-Vell in Universe X resulted in Nightcrawler finally learning the truth, and how the mix of his appearance and Catholic faith had made him the perfect tool for Mephisto to further his own schemes.
Realizing the truth, Nightcrawler finally adjusted to his original self and returned to New York City -- becoming a hero again by taking up the mantle Matt Murdock had left behind and becoming the protector of Hell's Kitchen. Finally, he found a formal position as the arbiter of heaven and hell in Paradise X. Using Limbo, now overrun with Dire Wraiths, "Belasco" could bring the souls of the damned who he deems unworthy of entering the paradise created by the heroes. In this small way, Nightcrawler could once again serve Heaven, even after being forced to more or less abandon that part of himself due to his transformation into Belasco.
It's a brutal fate for Nightcrawler in the Earth X-reality. For years, Kurt Wagner fought against the idea that he was a devilish figure. Despite his appearance, he was always one of the most pure-hearted of the X-Men, a genuinely faithful and optimistic man who did his best to protect a world that hated and feared him. And yet, thanks to the intervention of Mephisto, Kurt was forced to become the thing he feared most in the world.