What is in the "Warp Cage" that Abaddon wants to unleash?

[Defenestratus]

So the fluff from the Traitor's hate book has been summarized and it appears that the story surrounding the conflict between Chaos and the Blood Angels is that on that planet there is a pre-human artifact that is capable of "caging" a warp being. Chaos wants to unlock it with the "Banshee Stone" or something.

Rampant speculation time. What's in the cage?

I've got 100 oomlats on it being the Chaos space rat god.

Whats your guess as to whats in the cage?

[Mr Mystery]

That evil fart I did back in 2002 which cleared a shop.

So potent, it could easily have ripped a whole in space/time, thus winding up menacing the 41st Milennium.

[Asymmetrical Xeno]

An enslaver plague!!

(I Wish)

Probably be just a horde of boring mundane chaos daemons.

[Cutter]

Honey badger.

[Asymmetrical Xeno]

I'd be impressed if it turned out to be an ancient Yu'Vath artefact of some kind also.

[eldargal]

All the wimmins.

[Cactus]

Space Rat-god would be pretty cool...

My mind went to some Dark Eldar/Slaneesh thing. Perhaps it was word Banshee.

[son_of_volmer]

Primarch

[Psychosplodge]

Remember rotastak cages? It's like that but for miniature giant warp hamsters.

[Mr Mystery]

Gwyneth Paltrow's severed noggin?

[Renegade]

The soul of Horus, put their by the Emps? The fifth Chaos god? Archaeon?

[Bedroom General]

Them two missing Primarchs!

No Wait, I've got it! It's the opening of a wormhole between the Age of Sigmar and 40k. Bear with me. Imagine that Abaddon has learnt of a new group of Daemons and this is the way to summon them. Imagine his annoyance when its the Seraphon!! Daemons of Order. HA!
I can dream Can't I?