The eighth and current head of the Einzbern family. He wasn't around during Justica's era, but he has kept himself alive for nearly two centuries by continuously prolonging his life. He has a white beard that makes one think of a frozen waterfall, and Emiya Kiritsugu notices an astute light from his eyes that makes it impossible to see any senility and constantly brings about a feeling of bias and pressure every time Acht's gaze meets him.
(Source: Wikipedia)