The Oneirois are creatures of Nyx and Hypnos' servants. All of them were once human adventurers who fell into an endless sleep while exploring Hypnos' cave. While they were dreaming, their nature changes and eventually - sometimes after eons spent dreaming - they turned into titanspawns of Hypnos, bound forever to their master's will. Their main duty, however, is to ensure every humans can fall asleep and protect their minds during the process. They are fairly harmless as long as nobody interferes with their work, but if disturbed they can triffle with one's mind with a set of live illusions, mind traps or vivid nightmares.