While we are discussing corrupted Aura's end fate in the hands Alicia and/or Richard, isn't it strange that the Goddess also gave Richard and Alicia super powers to fight against the current Demon King Richard and his forces, and the Goddess didn't notice anything wrong about Richard and Alicia being demonic and evil? So I think that the Goddess did notice and is exploiting Roya's mortals to keep herself in divinity through belief-gives-power and doesn't care how many different Demon Kings rise and fall, because all she needs to do is bring in Otherworld mortals, give them power to take care of a problem she perpetuates and allows to exist. Or all of it's a delusion formed by Aura's mind while dying or because of her nerdy hobbies and having only two friends.
Also I could be entirely wrong because I'm at Castle of Wrath/Sathanas arc, and my theory is disproven in later arcs.