The Tower of Druaga: The Aegis of Uruk

Every five years, a summer comes when the demons in the mysterious Tower of Druaga lose their powers, thanks to a magic spell cast by a god named "Anu". King Gilgamesh, who rules the kingdom of Uruk, uses the demons' appearance as a reason to invade the tower and uncover its secrets. Over 80 years, the Uruk army pushed the demons back and built a fortress city and safe haven called Metz Kier on the first floor of Druaga. So begins the story of a warrior named Jil, who gathers companions along the way and sets out to find the legendary Blue Crystal Rod, a powerful artifact said to rest on the highest floor of Druaga. But other rivals, including the kingdom of Uruk itself, want the treasure too, each for their own reasons.