Sai Gekko

Sai Gekko (月光サイ, Gekkō sai) is the member of the Gekko Clan. He is referred to as the "ultimate master of the Shinto Temple".

Founding Heaven Tail
400 Years Ago, God made a pact with Sai Gekko along with Ribbons Gekko to create the Guild for every one to share the Peace and prosperity. As they finally finish the guild building, all four take a photo with the building in background as a sign that Heaven Tail is Born, and, in gratitude, after Sai and Ribbons' Death, the members of Heaven Tail make a grave inside the Temple of Heaven Tail.