Forgotten One from beyond the veil

Concept: “Worship him, fight him, have him as a dungeon boss, it matters not. He is eternal and omniscient.”
Content: An eldritch abomination from elsewhere
Writing: Includes stats and a table of strange effects that occur in the creature’s presence
Art/design: Blackletter font and line art on a white ground
Usability: Easy to use but probably pretty lethal