The ancient figure known for his judgment of souls in the afterlife is Osiris in Egyptian mythology. He serves as the ruler of the Underworld, overseeing the weighing of the heart against the feather of Ma'at, symbolizing truth and balance. Osiris's role signifies the importance of moral conduct in life and the hope for resurrection and eternal life. This process illustrates the Egyptian belief in the afterlife and the impact of one's actions on their fate.