Cult of the Ebon Flame
The Cult of the Ebon Flame was a Tzeentch Chaos Cult that was allied with the Thousand Sons. While serving in a large Thousand Sons force commanded by the Daemon Primarch Magnus, they were attacked by a Space Wolves strike force, sometime after the Great Rift's creation. Led by their Chapter Master Logan Grimnar, the Space Wolves had tracked down Magnus in order to claim their revenge for the Daemon Primarch's invasion of their Homeworld Fenris. In the fierce battle that followed, the Cult of the Ebon Flame and the Thousand Sons were destroyed by the victorious Space Wolves.