Warhammer 40k Ahriman Sorcerer

"Ahriman, greatest sorcerer of the Thousand Sons and architect of the Rubric that laid his Legion low, continues to walk the path towards salvation, or damnation. Searching for a cure for his Legion, he is forced to consider - was the great ritual somehow flawed from the very beginning? The answer may lie within the mysterious artefact known as the Athenaeum of Kallimakus, a grimoire of forgotten lore which is reputed to contain the exact words of the lost Book of Magnus or, perhaps, even a transcription of the primarch's deepest and most secret thoughts."