Despite coming off as bitter and grumpy through his speech, he has a gentle, tender, and modest nature. Diluc isn't very talkative and is one of very few words and at times, he can seem distant. Unlike his brother, Diluc is more introverted and often keeps to himself. Setting that aside, Diluc is very passionate when it comes to protecting Monstadt. He's an age regressor and is usually wearing diapers underneath his uniform. When regressed, he's very needy, childish and quite shy around others.