Helladikos
The planet is best known for being small, barren, and mostly worthless. However, it is extremely valuable to the forces of Chaos, for it is the 8th planet in its system, and occupies a favorable location for the Warp's favor.
Helladikon boats the largest remaining Warp Rift in the sector, hardly a Warp Storm, and nothing compared to the Eye, but in a desert, any water is precious. Cult remnants bitterly contest it, and their blood has soaked the world a dull red visible from orbit.
All the gods are worshiped here, but it is clear that Khorne keeps a closer eye on the planet than most. Here, demons can be found, here, warp weapons may be forged, and here, the Black Oracle interprets the will of the Gods, passing their desires to the mortal world even as his flesh is ever so slowly dissolved by the Warp Rift he lives directly beneath.