Oogie's Heartless has alot of dark powers, which include dark fire spells, greater control over bugs, and even acid/poison spells.
He is practicly Oogie Boogie's Nobody's brother, yet even he's disgusted on how the creeper behaves. but it doesn't halt is incredable unison and brotherly co-operation they have, incredable since Heartlesses and Nobodies are normally greatest of enemies.
After Maleficent was shockingly defeated and fell under Master Xehanort's control, all the remaining leagers were in fear. Lucky for the remainder, Xehanort had no particular use for any of them other than being future slaves to his empire once the cycle ran it's course. Although, he did warn them that only specifcally selected villains will be taken, and a certain starfish shaped sentient bag of bugs ended up on Old Xenny's want list. Oogie, however, did not need to be transformed because Xehanort already has a Heartless and Nobody that was currently in league with him. Still, the old master felt that he could use an Unversed version of Oogie to fill out the required Emotion Parasite trio. So, he had Oogie's Heartless and Nobody fuse back with one another briefly so that he could remove the negatron half of the original being, and make it into an Unversed Commander called the Bug King. Once there, the light half of Oogie was slain, and the Heartless and Nobody versions instantly reappeared once their required fusion time was over.
The Bug King, along side, the Heartless and His Nobody, were the three conquerers of Halloween town. when the lougers came to Halloween town in the darkness, Jack Skellington took it upon himself to battle the bug king alone, though quick to accept Sora's help, being aware of Xehanort's dispicable betrayal. Like with the normal Oogie, Jack was able to surpass the bug king, allowing Sora to trap all three incarnations of Oogie and fuse them all back together to recreate the original Oogie again alongside the pure light half that had disappeared before. Oogie was, of course, amnesiac like the usual moron he is, and denied that Jack actually helped him.