The Key of the Water Dragon God (水神竜の鍵 Suijinryū no Kagi) is a magical key that can summon Mercphobia.
Description[]
The key is depicted with a Sea Serpent body around the body in the shape of water waves with the Water Dragon's around the key's handle that has the same markings as those over Mercphobia's eye. The tip of the key is in the shape of a seashell.[1]
Usage[]
The key works similarly to Celestial Spirit Gate Keys, used by a Mage Summoner (召喚士 Shōkanshi) who uses a type of Magic to summon beings through Gates, this key in particular allows the holder to summon the Water Dragon God; Mercphobia from anywhere in the world.[1]