The powers that mutants develop in the Marvel universe are similar to the magical abilities used by characters in the Dungeons & Dragons multiverse, especially those who gain them from bloodlines. There is one character from the X-Men who is tailor-made for appearing in a Dungeons & Dragons campaign and that is mutant superhero Betsy Braddock, better known as Psylocke.
Psylocke debuted in Captain Britain, but she was integrated into the X-Men comic books and became a staple of the team. She is a powerful telepath, who can manifest her psionic energy into a blade, which she can use to strike her enemies and damage their minds. Psylocke was also a character who was known for her fanservicey outfits, which made her a popular choice for cosplayers around the world. Despite this, she hasn't been given much representation in the X-Men movies & TV shows, at least when compared to other members of the team. Psylocke's powers haven't always been as impressive when compared to the other members of the team, but she has acted as a leader of the X-Men on a number of occasions, thanks to her incredible combat skills and her ability to keep calm under pressure.
The version of Psylocke we have created uses material from the Player's Handbook and Unearthed Arcana. It bears mentioning that the content in the Unearthed Arcana article is considered playtest material and it needs to be cleared with the DM before use. Psylocke is a human (non-variant) Rogue, who takes on the Soul Knife archetype at level three. Using the basic stat spread listed on page 13 of the Player's Handbook and taking her race into account, Psylocke's starting stats would be STR 9, DEX 16, CON 14, INT 11, WIS 13, and CHA 15. The Soul Knife archetype from Unearthed Arcana is the perfect fit for Psylocke, as it allows her to create blades of mental energy that can deal tons of damage to foes who are struck with it, especially through sneak attacks. She also gains basic telepathic communication abilities from the archetype.
Psylocke has one of the most convoluted backstories in the history of Marvel (which is no small boast), but we've decided to focus on one aspect in order to fit her into a D&D campaign, which we'll explain in more detail at the end of the article. Psylocke's backstory is Criminal, based on her training with The Hand. Her starting skills would be Deception, Stealth, Acrobatics, Investigation, Persuasion, and Sleight of Hand. If the variant Feat rules are used, then she would benefit from Alert, Charger, Defensive Duelist, Grappler, Mobile, or Skulker.
In terms of alignment, Psylocke would fall into Chaotic Good. Like the other members of the X-Men, she fights to protect the world that hates and fears her. The X-Men exist outside of the boundaries of the law and are often opposed by the governments of the world, yet they risk their lives to face super villains and cosmic-level threats whenever they are needed.
Psylocke's bizarre backstory would be hard to implement as-written into a D&D campaign unless you jump on at a certain point. In the X-Men comics, Psylocke started out as a caucasian woman from Great Britain. The team fled into a magical portal called the Siege Perilous and were scattered across the globe. When Psylocke returned, she was an Asian woman in China. It was explained years later that she was used as part of a magical experiment to save the life of a woman named Kwannon, which led to their minds being switched into different bodies. The two women had their memories messed with, and they believed that they were the other person for the longest time.
When using Psylocke as a D&D character, the Kwannon/mind-swap backstory would make for an interesting concept. The original character was a criminal/assassin, who woke up in a different body that possessed psychic abilities. Psylocke is on a quest to discover what happened to her, which could tie into any number of D&D campaigns, especially as she tries to come to grips with her new abilities. It's possible that she could encounter her original body and its new inhabitant during the quest, which could have any number of outcomes. Perhaps the new bearer of the body is on a quest for revenge, as the reason for the swap was because Psylocke had been contracted to kill her, but it happened during a magic ritual and it went awry? The player should clear this backstory with the DM first, as it's something that can be incorporated into the game and used at a dramatically important moment. Psylocke's powers are easy to incorporate into D&D, but her backstory needs a little work in order to fit it into an established campaign world. There is a lot of potential for working the Betsy Braddock/Kwannon story into a D&D game, so long as the DM is fine with incorporating it into the story.
Source - Unearthed Arcana