laios_touden_(demon_king)
A what-if version of Laios_Touden as a dungeon lord, from one of Ryoko_Kui's extras.
Since he isn't canon, "Demon King Laios" can't be considered spoilers on his own, but in fanarts, he's sometimes paired up with spoiler-y characters. Please add the corresponding_tag when that's the case.
Also, consider adding alternate_universe.