Darius had tanned skin, short unkempt black hair and small light silver-colored eyes. He wore the typical uniform of a member of the Scout Regiment.
Darius is present while Erwin gives the recruits a speech. When Erwin informs the recruits of the Scouts' high mortality rate, Darius attempts to warn him not to be too hard on the troops, lest none of them join.
When the gate is about to be open, Darius expresses that humanity will take another step forward and encourages the recruits to show what they are made of.
During the 57th Exterior Scouting Mission, his team comes into contact with the Female Titan. Darius fires a signal flare at the Titan to distract it and give his team time to attack it, but they are each killed in short order. Darius attempts to flee from the village to warn the other members of the power and unpredictability of the mysterious Titan, but his horse is not fast enough to escape its sight. The Female Titan catches up and kicks him and the horse into the air, killing them both instantly.
During the Battle of Shiganshina, as Erwin Smith begins to lament the dwindling hopes of his dream, Darius stands among the many fallen Scout Regiment comrades in Erwin's mind, wanting to know if their deaths had meaning.