A red-haired young man who serves as the owner of Dawn Winery, Mondstadt's largest winery. He once held a high-ranking position in the Knights of Favonius.
Since becoming owner at a young age, he has demonstrated the judgment and intellect to revitalize the winery in a short period. He possesses broad knowledge, ranging from mastery of all types of weapons including swords and bows to playing difficult musical instruments, and is well-versed in cooking and chess.
Due to personal reasons, he possesses a strong sense of responsibility and duty that leads him to distrust public servants. While keeping his distance from the Knights, he works behind the scenes using his wealth and information network to the fullest, and fights monsters that threaten the people by night, single-handedly dedicating himself to protecting Mondstadt.
His secret activities have led Mondstadt residents to rumor of a "Darknight Hero," but he has no good feelings toward this name, finding it both embarrassing and cringing at the naming sense.
As a result, he lives a life of extreme busyness as both a winery owner and a shadow hero, and at night, he sometimes stands as a bartender at his own tavern, Angel's Share. One wonders when he sleeps.
Diluc was once surrounded by flowers and applause, with great expectations placed upon him by those around him.
He manifested a Vision at age 10, joined the Knights of Favonius at his father Crepus's wish, and eventually became the youngest Cavalry Captain at age 14.
From a young age, he bore his father's expectations and was a child who disciplined himself strictly; he was reportedly a serious child who would freeze in confusion if told by his father he was free to do as he pleased.
What made him happiest was "being praised by his father," and he revered his father to a point of near-blindness.
However, to save his father from the agony of a Delusion's backlash, Diluc had to end the life of the father he most respected with his own hands. Since then, he has lived suppressing his various emotions.
Following this incident, he resigned from the Knights, discarded his Vision, and wandered the seven nations to uncover the truth behind his father's death.
Even now, his father remains a lingering pain. Diluc became the hero who inherited his father's will.
He is willing to sacrifice himself for a greater cause, but he is not a man indifferent to the pain he feels in the process. Diluc rationally understands the necessity of facing challenges and moving forward for the sake of others.
On the other hand, he is tormented by a sense of responsibility that pulls him away from his gentle past, and he struggles to discard those emotions, possessing both mental strength and fragility.
