Loptous is a Wicked Earth Dragon from Fire Emblem: Genealogy of the Holy War acting as Deity for Loptr Church and the overaching villain of the setting.
He mainly remained in the world thanks to the blood pact he made with Gair, who desired Loptous' power; Gair ended up getting Loptous' blood as well as an evil spellbook with the remaining of his powers named after the dragon himself; in exchange, the wicked blood along with the book allowed Loptous to use Gair and his descendents as vessels.
