I like to think Dimitri is pretty calm under pressure. Like, he's internally panicked and freaked, but he acts more than feels. Like that time he was in the out of control train (Anastasia movie), did not hesitate to jump and check the front of the train to see what was wrong and then make plans succeeding that moment during the whole predicament. And in the final battle, no question about how the hell Anya got into another mess and just straight up punched an evil guy with dark magic like it's going to be some simple street fight. No "what the hell is all this shit" just "questions later, punch now" and I think I just love that about him; a man of action.