Darius was an older man with avarage height and build, he had tanned skin and short unkempt black hair that he kept slicked back. He wore the typical uniform of a member of the Survey Corps.
Darius is present during Erwin Smith's attempt to recruit trainees to the Survey Corps. When Erwin informs the recruits of the Corps' high mortality rate, Darius attempts to warn him not to be too hard on the troops, lest none of them enter the Survey Corps.
During the 57th Expedition, his squad tries to ambush the Female Titan. As each of his squad members are 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 Survey Corps comrades in Erwin's mind, wanting to know if their deaths had meaning.