Some TMNT stuff really isn't for little kids.
In the IDW comics Darius Dun lives in the 21st century and is financier and boss of the local version of the Street Phantoms there. Although he was a gifted athlete in his high school days, Dun recognized early on his business acumen and the advantage he could create through the right contacts. This was one of the reasons that he committed the inventor Libby Meitner to get a grip on the underworld of New York City with her talent.
His plans to consolidate his criminal empire led to a fierce warfare with the Foot Clan under Splinter's leadership. Even though their high-tech weapons first gave the Phantoms an enormous advantage, the Ninja Turtles were able to re-establish the rift with the help of Libby's ex-husband Harold Lillja. In the end, the Foot Clan defeated the Phantoms, and Splinter vanquished Dun in a duel.
In issue #64, Darius Dun is captured during a raid by Splinter's Foot Clan. Splinter offers to spare Dun's life if he surrenders all of his assets to the Foot Clan, but Dun refuses. Splinter then coldly orders Jennika to execute Dun on the spot. This killing prompts Splinter's sons, Leonardo, Raphael and Donatello to cut ties with Splinter and the Foot Clan, which Michelangelo had already done in issue #50.
However, Dun was not finished with the Turtles. In Teenage Mutant Ninja Turtles/Ghostbusters 2, he returned as an angry ghost who summoned the interdimensional demons known as the Collectors and sent them after the Turtles. His original goal was to imprison them for the rest of Splinter's life, and watch Splinter's agony at never knowing what happened to his sons.
When he summoned the Collectors for the second time in order to berate them for their failure, they devoured him. However, his essence possessed them and transforms all four into Darius Dun. They pursued the Turtles back to the Ghostbusters' dimension, where they were attacked by both the Turtles and the Ghostbusters. The Ghostbusters succeeded in opening a dimensional gateway that sucked all four Duns into their storage unit, from which they would never be able to escape.
- Unlike his original character from the Teenage Mutant Ninja Turtles: Fast Forward TV series, this version of Dun has no apparent relation to the Jones Family.