Question: Sagas of the Demonspawn is a four issue gamebook series written by J. H. Brennan, and who illustrated the latter two, by which British fantasy and science fiction illustrator and modeler known for his work for Games Workshop's White Dwarf magazine, Warhammer Fantasy Battle, Warhammer Fantasy Roleplay and Warhammer 40,000 games?
Sentence (from "Chaos (Warhammer)"): Further similarities can be seen with the godlike extradimensional Great Old Ones of horror writer H. P. Lovecraft's stories.
Relevant evidence: No