Nocturne, whose real name is Talia Josephine "T.J." Wagner, is a mutant from the alternate reality designated Earth-2182 in the Marvel Universe. She is the daughter of Nightcrawler (Kurt Wagner) and the Scarlet Witch (Wanda Maximoff), inheriting her father's distinctive indigo fur, yellow eyes, prehensile tail, pointed ears, and demonic physique, along with enhanced agility, wall-crawling abilities, and the capacity to blend into shadows. Her mutant powers include firing destructive hex bolts—energy projectiles drawn from an extra-dimensional source—and a unique possession ability, allowing her to displace a host's consciousness and control their body for limited periods, initially leaving the host comatose but later refined through experience. She first appeared in a cameo in X-Men: Millennial Visions #2000 (August 2000), with her full debut in Blink #4 (June 2001), before becoming a central figure in the Exiles series.
In her native reality, Nocturne grew up in secrecy due to the outlaw status of the X-Men and trained at Xavier's School, eventually joining the team under Wolverine's leadership. She formed a romantic relationship with teammate James Proudstar (an alternate Thunderbird), which ended tragically when she suffered a miscarriage following his placement in a coma after a battle. Subsequently, she was recruited by the enigmatic Timebroker—an illusion created by insectoid entities—to join the reality-hopping team known as the Exiles. Alongside members such as Blink, Mimic, Morph, and Thunderbird (from another reality), Nocturne undertook missions to repair damaged timelines across the multiverse, preventing catastrophic alterations to their home realities.
Nocturne's tenure with the Exiles involved numerous high-stakes adventures, including confrontations with Mojo in the Mojoverse and defenses against threats like Mad Jim Jaspers. A significant turning point occurred when overuse of her possession powers triggered a severe stroke, leaving her comatose and stranded in the main Earth-616 universe. After recovery through physical therapy, she joined New Excalibur in London, contributing to battles against foes such as Black Tom Cassidy and the Warwolves. Her experiences also deepened her bond with an alternate Thunderbird, leading to further multiversal exploits and temporary leadership roles within reformed Exiles teams.