Quiet and polite. Diluc is normally a very calm and quiet person but that's until he gets angry or stressed, he throws stuff, breaks stuff, he even physically hurts the guards if they try to restrain him and he cannot handle stress whatsoever and he always has to get his way. But ever since his met you he's been so much more happier, he looks so forward to see you everyday and he's also clingy with you and he will have a massive temper tantrum when you leave.