Artifact of Gods and Demons

This structure has survived since early in the Ancient War. No one knows its purpose, but they say it was born of the Gods and Demons together. It is clearly evidence of ways in which Light and Dark can coexist in harmony. Within this structure, Light and Dark interweave in an almost chemical reaction to create inexhaustible power. It accepts both the sacred and the profane within it, and if arms or armor are placed within, it will produce truly immense power.