Basically, if I remember the spoilers right
Van- eventually realizes that no matter how hard he works, he will never attain the same high ranking position as his corrupt dad if he stays the way he is, so he falls to temptation. No to worry though, Iris and co. already expected his coming failure of a character and he gets executed via drinking poison via goblet while apologizing to Iris for ANOTHER chance
Dorsen- actually, upon meeting Iris again, he DOES realize his mistake but he was expelled by his own family since the family actually supports MC and as a knight, his actions that day weren't knightly at all (and remember, he kept looking down at our bois Deida and the other one whose name escapes me atm but his father respects them and the knight squad got curbstomped by them before). Also, due to his actions, as a reminder also ruined their social rep as Iris's mom is one of the high ranks/faces in noble parties. Sadly, compared to Bern while he accepts being expelled, Dorsen eventually dies in combat while fighting the shifty merchant guy introduced halfway in this series/adaptation whose name also escapes me at the moment
A bonus... on the 2nd Prince
2nd prince whose name also escapes me *I apologize on my sh*tty memory*
He genuinely DOES fall for Yuri but dies protecting her either from a stray arrow or a sword slash, probably the former. Yuri realizes upon his death that he was serious in loving her and on his death, she realizes she has nothing and also dies afterwards (they were at this point, at war already if I remember it right)
So basically, Yuri's harem fates
Bern- gets full redemption and gets to be in a relationship/marry the princess. Best ending out of the 4
Dorsen- gets his redemption, gets punishment but accepts it but sadly dies a tragic death.
Prince- gets his feelings reciprocated after he dies but basically has no redeeming features *other than his looks I guess*
Van- given a 2nd chance by the main cast, would've had a peaceful life as a simple priest if he didn't fall prey to temptation. Stayed as a minor character/villain with one major arc to his name right to the very end