truth

Truth is the commonly used name for the enigmatic and ethereal entity that resides before The Gate, addressing alchemists who have ventured into God's domain through alchemy. It manifests as a pure white, nearly formless being, barely distinguishable from the surrounding endless white expanse, except for a shadowy outline that mirrors the shape of the person it speaks to, reinforcing its claim to be another aspect of that individual. When Edward and Alphonse Elric each appeared before the Gate, Truth took on the appearance of a young boy. For Izumi Curtis, it reflected the form of a young woman, while it appeared as a vigorous man to Roy Mustang and a white version of Father’s flask form. Initially, Truth introduces itself as the entity some call God, the World, or the Universe, seeming welcoming and jovial at first but quickly pointing out the arrogance of those who seek it. It then opens the Gate, forcing them inside. At this moment, Truth often smiles with an eerily wide and insane grin, similar to that of the Homunculus Gluttony and Father. Upon returning from their journey through the Gate, alchemists are informed by Truth about the toll required for accessing the Universe's knowledge. This toll is usually collected in the form of a body part, which disintegrates from the alchemist and reappears on Truth's form. In this way, Truth is responsible for taking Edward's left leg and right arm, some of Izumi's internal organs, Roy's eyesight, and Alphonse's entire body. It seems that Truth's goal is to discourage humans from venturing into God's domain. When Edward returns and sacrifices his arm to recover his brother's soul, Truth calls him a fool. (Source: Fullmetal Alchemist Wikia)