T.J. Wagner is the daughter of two of her reality's most successful heroes, Nightcrawler of the X-Men and the Scarlet Witch of the Avengers. She was raised primarily in the X-Men Mansion. Her mother continued to serve with the Avengers separated from Nightcrawler since her parents were unable to effectively go on missions together without compromising their team's safety. Nocturne trained hard and eventually became an X-Man. She fell in love with her fellow X-Man, James Proudstar, and had a tumultuous relationship with him.
Nocturne awoke one night to find herself unhinged from time. The mysterious Timebroker informed her if she did not join the Exiles her father would die at the hands of Mystique during a battle with the Hellfire Club.
Nocturne soon found she disliked the life-or-death missions but she enjoyed her new team. She began to fall in love with her teammate, T-Bird. Ironically, T-Bird was John Proudstar, the other reality older brother of her boyfriend. The relationship was a rocky one, but the two were able to work it out and stay together.
On a world where the Exiles were being held captive by the Skrulls, Nocturne discovered she was pregnant. Nocturne told T-Bird and both were excited about the impending birth. Unfortunately, T-Bird sacrificed his life on that same world to drive Galactus away from Earth. Nocturne hoped the Exiles would be able to wait for John to recover from his wounds but the team was forced to leave T-Bird behind. Nocturne eventually lost the baby and spent a lot of time away from her teammates despite their offers of support.
In a reality taken over by a Warlock infected Legacy Virus, Nocturne and her teammates were informed by the Tallus that they must defeat the Vi-Locks. Nocturne volunteered to pilot a plane filled with nuclear weapons into the Vi-Lock Hive. Mimic nerve pinched her and took her place. Mimic survived and the team moved forward, victorious.
On a mission in the Marvel Universe (Earth-616), the Exiles were forced to leave Nocturne behind. Exodus invited her to join his new Brotherhood of Evil Mutants and she accepted in order to infiltrate their team. During their assault on the X-Mansion it appeared as if Nocturne had been killed by the Juggernaut but that was not the case. Nocturne helped the X-Men defeat the Brotherhood, but unfortunately she and the rest of the Brotherhood were sucked into the portal in Xorn's head. She ending up in Mojo's realm, before escaping back to Earth-616. With the Juggernaut, she has recently joined the new incarnation of Excalibur.