Niflheim, the Underworld, also referred to as the Daemonium, is the world of demons. It was previously connected to Aselia when it was a planet devoid of life and mana, but the arrival of the comet Derris-Kharlan 10,000 years prior to the World Regeneration brought about the sealing of this connection by Ratatosk; this put an end to the substantial demonic influence in Aselia and gave way to the flourishing of life. The demons seek to reincorporate Aselia to their realm at any cost.