Biblos

Biblos is the 'black demon-god' summoned in the coastal kingdom of Bertea by means of forbidden heretic magic. Roynas Volm sacrificed his own sister to perform the summoning, thereby destroying Bertea's capital.

Biblos appears as a twin-sword beast covered in red runes, and it endlessly spawns imps. It is uncontrollable and brings nothing but destruction.

In the war for Bertea, King Ars personally led the campaign and defeated Biblos, as he had once done in a prior demon-god incursion.