An AU were the Celestial Bodies of the Solar System are the Souls of certain Monsters. Example: Asgore's soul is the Sun, Toriel's is Earth. Human's and normal Monsters live on the Earth still but there was no war and everyone has magic. The "Boss" monsters that have the planets as souls can pick humans or monsters to imbue their moon/natural satellite with consciousness. Example: Frisk is the Light Side of the Moon while Chara is the Dark side of the Moon.