Thanks for the translation!
So the ancient civilization that made the dungeon below summoned and used the Winged Lion during their time, and later on the demon became some sort of "guardian deity" figure to the people of the Golden Kingdom, who had inherited that region... not gonna lie, it seems awfully easy to create religions based on demons in the Dungeon Meshi world, as ironic as it may sound, lol.
Also, I find Thirstle as the dungeon master very interesting. Even though his self-sustained circle of paranoia renders him insane, it's exactly that why he never was consumed by the Lion; He doesn't show weaknesses to be replaced, his unending desire to keep everything perfect means he's never satisfied, and his distrust for everything prevents him from being manipulated.
Anyways, good chapter. Hope to see some Laius vs Thistle next, shit's finally gonna hit the fan.