Summary
Truth is the most common designation for the enigmatic and ethereal entity that resides before the Gate, confronting alchemists who have transgressed into God's domain through the practice of alchemy. Visually, it manifests as a pure white, nearly formless figure that blends seamlessly into the endless white expanse surrounding the Gate, save for a shadowy outline that mimics the appearance of whoever it is addressing. This reflects its assertion of being merely another shade of that individual. When Edward and Alphonse Elric stood before the Gate, Truth assumed the form of a young boy; for Izumi Curtis, it appeared as a young woman; to Roy Mustang, it took the shape of a vigorous man; and for Father, it resembled a white version of his flask form. Truth initially identifies itself as the entity known to some as God, the World, or the Universe. It initially appears welcoming and jovial to its visitors before highlighting their hubris and opening the Gate, which drags them inside. Upon this event, Truth often displays an eerily wide and insane grin, reminiscent of the Homunculus Gluttony and Father. When an alchemist returns from their journey through the Gate, Truth explains the necessary toll for accessing the Universe's knowledge and collects it. This payment is typically a body part that disintegrates from the alchemist and reappears on Truth's form. Through this mechanism, Truth is responsible for taking Edward's left leg and right arm, several of Izumi's internal organs, Roy's eyesight, and Alphonse's entire body. It seems Truth's objective is to deter humans from entering God's domain, as evidenced by it calling Edward a fool when the young alchemist returns and sacrifices his arm to recover his brother's soul.
