Tyne inherited some of his powers from his father, Ben Reilly, a clone of Spider-Man. After Reilly and his mother died, he went into foster care. When he reached puberty, his spider-powers manifested themselves, along with the degeneration that affects all the Spider-Man clones. Another such clone, Kaine, tried to halt the degeneration by placing Tyne in a cloning chamber. Kaine also told him about his heritage. When Daredevil (Matt Murdock) was mortally wounded in Kaine's defense, Kaine summoned Zarathos to save him. The demon, realizing that Daredevil would not survive, instead entered Tyne. Daredevil's newly released soul followed it and managed to exorcise most, but not all, of Zarathos's presence. Tyne can now call upon the memories, skills, and guidance of Daredevil, as well as some of the demonic powers of Zarathos. The experience halted the painful degeneration but gave him a demonic appearance, with red skin, yellow eyes, horns, etc.
Tyne soon learned how to give himself an illusory human face, which appeared older than his true age. He went to law school and became an intern at Murdock's old firm. He also became a costumed crimefighter and created an outfit that resembles Daredevil's. He worked with Spider-Girl on several occasions, battling Crazy Eight, Killerwatt, Funny Face, and Mr. Nobody. On his own he has fought against the Kingpin, Venom (Normie Osborn), and the Goblin Queen. Zarathos reappeared after Venom and the Goblin Queen almost killed Darkdevil and tried to re-establish control. Doc Magus had to journey into Tyne's mind to drive out Zarathos; within he found Tyne (at his true age), Daredevil, and Zarathos manifesting as Ghost Rider. Tyne was forced to battle Spider-Man in a plot by Loki.
Teleportation: Darkdevil can instantly transport himself to a place he can see or has previously visited.
Fiery Objects: Darkdevil can summon solid flame in any desired shape, although he typically uses a billy club like Daredevil's.
Healing Factor: Darkdevil recovers from injury at superhuman speed.
Spider-Powers: Like Spider-Man, Darkdevil has superhuman speed, strength, and agility; a spider-sense that warns of danger; and the wall-crawling power.
Darkdevil has no exact counterpart in the mainstream Marvel Universe (Earth-616).
Darkdevil's name at birth remains unrevealed. After being possessed by Zarathos and Matt Murdock, he assumed the alias "Reilly Tyne".
Tyne's relationship to the Parkers depends on how the relationship of Parker and Reilly is defined. As given above, they are assumed to be "brothers." Given that Parker and Reilly have identical DNA, May Parker could also be considered Tyne's half-sister.
Hints about Darkdevil's true identity in early issues of Spider-Girl led many fans, as evidenced by the book's letter page, to theorize that Darkdevil was in fact Ben Reilly himself.