The Collectors

Some TMNT stuff really isn't for little kids.

The Collectors are a quartet of demons who can be summoned to track down and erase any entity, at the price of the soul and sanity of the summoner. They take on a wicked reflection of their quarry.

In Teenage Mutant Ninja Turtles/Ghostbusters 2 issue #1, Darius Dun tasks the Collectors to track down and entrap the Ninja Turtles in a ghostly prison. The Collectors did this, but the Turtles managed to escape through the intervention of their Ghostbusters allies. The Collectors chased the Turtles from one dimension to another, enraged that their victims had escaped them.

Dun then summoned them a second time to demand to know why they had failed him. Irked, the Collectors decided to enact their price by devouring his entire spirit. However, they were then possessed by Dun's essence, becoming a new four-member demonic entity who was simultaneously both Darius Dun and the Collectors.