Messor is the God in charge of Mortios. He, like the rest of the Overgods posess true Immortality and Omnipotent power over his planet.
Messor keeps an eye on his planet at all times, He is usually very focused on making sure that his planet remains what it should be.
Messor was the one who created the planet known as Mortios. And with Vita's consent they linked their planets, making Mortios a kind of afterlife for the people of Nai-Tros.