Death Ninja started out as one of the many hired ninjas by Deathwatch. During one of Deathwatch's missions, Death Ninja was killed by Ghost Rider. He was also Ghost Rider's first victim.
Months later Centurious's men found his body and brought him back to life. He joined the FIRM. In the end, the only way Death Ninja could die, is if he killed Ghost Rider.
Death Ninja would then go on a murder raid and eventually fought with Ghost Rider on the subway. He lost.
He would return to fight Ghost Rider again. Oonly this time Suicide was in on the fight, as well as Heart Attack. During the fight, Micheal Balendino let loose a rocket on all 4 of them. After the explosion, Death Ninja's body was not found.
Months later, the Death Ninja appeared alongside of a collection of former Ghost Rider villains, under the employ of Danny Ketch (who is no longer Ghost Rider). The group was sent after Caretaker. During the battle Caretaker shot the Death Ninja with a hellfire shotgun, seemingly destroying the ninja for good.