This is just based on that one sentence introducing Dimitri, but I bet that he will end up being some Kind of Yandere archetype. It just seems weird to me to Mention that he holds "a tinge of darkness" or smth in him. Also I think that, if you pick his house, there will be a heavy Focus on the rivalry/ dynamic between him and Claude, though this is just based on a gut Feeling that Claude is most likely the smartest/most talented out of the bunch but just Plays the clown most of the time. I think something along the lines was shown in of the screenshots in which he mentions that there must be something only Byleth/Beleth knows, though None of the other two got this Kind of characterization. I could be Looking into it too much, but who knows. The "high strung perfect prince burdened by pressure"-type vs. "the aloof Genius"-type isnĀ“t too farfetched. One Thing I am sure About though is that Raphael is gonna be Benny 2.0, which is fine with me.
Edit: fixed some spelling