Hausōs, the Goddess of the Sun and Moon, and the original Hyperborean alicorn.

A ‘conglomerate’ deity, prior to taking on a physical form when she settled on a world Hausōs had been two separate alicorn souls; one of the Sun, and one of the Moon. Both were heavily damaged in the First War against Chaos (Discord’s kin), that the only way for either of them to survive was to join together. While Hausōs was usually of one mind, she occasionally displayed thoughts and tendencies more like that of one of her original components (think Garnet from Steven Universe).

While the world under her careful watch was a peaceful one, it was not to last. Hausōs was slain by a demon king and queen that trespassed upon Hyperborea, her city sunken and all knowledge it possessed destroyed. While she managed to send both back to Tartarus, she eventually succumbed to her wounds and passed away in the Prench Pyrenees several thousand years before Caroline and Asriel arrived, using the last of her power to allow the sun and moon to move themselves.