Hellraiser/WMG

Kristy Cotton is slipping to the Dark Side.
Kirsty Cotton from Hellraiser is becoming more corrupt and darker as Hellseeker rolls around... She keeps making deals with Pinhead to save her own skin (literally). She's going down the same path as Julia.

Even in Hellraiser II, she was showing subtle signs of this:

"Kirsty Cotton: I didn't open the box!

Female Cenobite: "Didn't open the box." And what was it last time, "Didn't know what the box was?" And yet, we do keep finding each other, don't we?

Pinhead: Oh, Kirsty. So eager to play, so reluctant to admit it."


 * The novella that the first movie was based on ended with her as the puzzle box's new owner and implied that she'll sell it to people just like the antique dealer did. So this is plausible.

Pinhead is Erno Rubik.

 * Debunked in the very second film (further debunked by the fourth film, which shows the box being made in the 1700s), although considering "Pinhead" can exist without Elliot Spenser and that there are apparently several different incarnations of the Chatterer, perhaps the cenobites are spirits that simply merge with humans who take very well to the tortures within the box. With that in mind, perhaps Rubik is one avatar of the non-merged-with-Spenser spirit form of Pinhead. ._.

The Cenobites are daemons of Slaanesh.
Obvious, really.
 * Actually an interesting thing about the Cenobites is that despite their nature and appearance, they are creatures of order, not Chaos, and so being the servants of a Chaos god would be the last thing they could be.

Hell in Hellraiser is really Malkuth's Citadel, from KULT.
The puzzle box is a portal. Hell is really Metropolis, and the Cenobites are Awakened Human servants of the Archon who are attempting to help the other human captives Awaken. They even imply the box is for seekers of knowledge after all...

The Cenobites are Keepers.
They simply come from a part of Arcadia that happens to be particularly twisted and unpleasant. They take all those who open the Lament Configuration to become their Changelings, and eventually evolve into more Keepers.