Voidoxity

In a world where the roles of Light and Darkness had shifted, there were two powerful individuals chosen by the Old Divines . . . They were given the titles of Ascension and Chaos as recognition of their ferocious might.
A millennia after his wife and son were murdered, Aergos-the Demon King, Lord of Chaos, and ruler of the lost kingdom of Amedus-wakes up alone in the Void Realm, stripped of all memory. With the help of his son's spirit, he learns of his kingdom's destruction at the hands of Elysium, the cruel Holy Priestess and daughter of Cydius, the Lord of Ascension and ruler of the rival kingdom of Requiem. Desperate to restore balance in the world and stop Elysium's ongoing reign of terror, Aergos traverses immaterial planes and finds his way back into the realm of the Gem of Purity, where he was first banished on that fateful day a thousand years ago. There, he discovers his access point to the world he once knew: a magical mirror.
Enter Kisara, a maid to King Cydius, condemned to a life of servitude. After discovering the Gauntlet of Edin, a powerful relic embedded with the Gem of Purity wherein Aergos is trapped, she makes contact with the Demon King. Both seeking freedom from their respective prisons, Kisara and Aergos make a pact to uncover the truth of Amedus's destruction and the whereabouts of the evil Holy Priestess. Kisara dons the gauntlet, creating a telepathic link with Aergos, and escapes Requiem. Together, the unlikely duo encounter unholy beasts, pitiless villains, and supernatural allies, harnessing the power of Dark magic to uncover and destroy the plague of corrupted Light.
This is Aergos's last chance for redemption, and blood will stain the earth before peace even has a chance to be restored.