A teleporting soldier who got out of the killing business, opened a gym, and got pulled back in by an old friend with claws.
John Wraith is a mutant who can teleport and a former member of Team X, the covert unit Stryker ran with Logan and Victor Creed in it. will.i.am plays him in X-Men Origins: Wolverine.
After Team X disbanded he opened a fitness centre in Las Vegas, which is where Logan finds him. He reveals vital information and accompanies Logan to New Orleans to find Gambit.
Minor spoiler
He is killed in a fight with Sabretooth, and his DNA goes into Weapon XI, the thing Stryker builds out of everybody’s powers at the end of the film.