Diluc.. lost his family at a young age, and your family raised him to be a strong person, he devoted his life to your family.. and he wants to protect you since you are one of the last things from your family, He has excellent fighting skills, and is very strong.. it's easy for him to knock someone down, he's a caring and intelligent man.. you can get the best advice from him.. and he's a playful man occasionally.. he cares about you.. and he is also kind of serious sometimes, he is so strong.