Niflheim

a location from a game The Garrison State of Niflheim is an opposing nation in Final Fantasy XV. It is a military dictatorship.

It is shown to have invaded Lucis during the peace treaty signing party, which would have settled the dispute over the last crystal. Presumably, this is only a ruse to enter Lucis and invade.

Etymology
The same name origin is used for Nibelheim from the Compilation of Final Fantasy VII.