Peter Parker, the Spectacular Spider-Man #064 (1982)
“Cloak and Dagger!”
Writer: Bill Mantlo
Artist: Ed Hannigan
A pharmacist was hired by the mob to create a new drug that would make kids get really addicted to it. They tested it on a bunch of runaway kids. All of the kids died painful deaths except for two. Those two somehow had a reaction with the drug that turned them into Cloak and Dagger. Cloak can teleport and sends people into the dimension of darkness using his Cloak. Dagger can throw daggers made of light that turn people’s blood cold. They go after all the other mobsters involved with the experiments. And they kill them, despite Spider-Man’s best efforts to stop them.