Lothric is a pale, skinny young man. He has long, claw-like fingers and grey-ish hair. He is said to have only ever worn one robe throughout his life. Lothric relies on magic alone during battle, and is a considerably powerful magic user.
Lothric is thought to be the son of King Oceiros and the younger brother of Lorian and the ambiguous Ocelotte. From birth, he was destined to be a great warrior and a Lord of Cinder. He was beloved by the royal family despite being born a frail and shriveled child.
His older brother, Lorian, decided to share the burden of Lothric's curse and was rendered blind, mute, and mostly unable to stand as a result. When the bell tolled to call the Lords of Cinder, Lothric did not answer the call. He implies it was because he has no desire to assume the mantle of Lord.
At one point, Lothric was expected to wield a platinum straight sword and become a champion, but possibly due to his frail health, this became a distant dream forever.