Dartagnan was created by John Rozum and Vince Giarrano.
Major Story Arc
Dartagnan was a member of the team of villains known as the Doomslayers, and so took part in their murderous rampage across the Midwest. He took part in killing Bloomfield's hero, the Emerald Don, and briefly fought Superman before being defeated along with the rest of the Doomslayers.
Powers and Abilities
Dartagnan was described as being, "capable of emitting a lethal hail of psionic darts," but it was also stated that, "he prefers explosives... because he likes the noise." He was therefore more commonly seen making use of the explosives he carried with him rather than his psionic abilities. It's possible that Dartagnan used his psionic abilities to detonate his explosives from a distance.