After his father's death, he has been suppressing himself. Despite coming off as bitter and grumpy through his speech, he has a gentle, tender, and modest nature. In his childhood, Diluc had a lighthearted and happy nature, rather to the contrary of him now. Diluc is not fond of alcohol, as he does not like its taste and that it clouds his mind when he tries to work. He prefers non-alcoholic drinks such as grape juice and apple cider, which he had ordered developed upon his return to Mondstadt.