various
Call of Archaon
part 4

Three champions of Chaos are roused from the ongoing war against Sigmar's servants and compelled to journey into the heart of darkness. Their goal? To serve at the side of the Everchosen himself, Archaon, as one of his Varanguard. But the trials before them are many, and not all will survive...
Age of Sigmar
novel

It contains:
Eye of the Storm
Beneath the Black Thumb
Knight of Corruption
See No Evil
In the Lands of the Blind
Blood And Plague
The Trial of the Chosen
The Solace of Rage

Also in:
Mighty Battles
The Realmgate Wars: the Novels
The Realmgate Wars: Volume 2