First, I want to make clear that this is just my own opinion and I have no intention to offend anyone.

I just don’t think the author did a great job developing the 端王 chatacter. I mean, he is a completely different person in the first section and the third section of the story and the change was very abrupt and unnatural.

My first impression of 端王 was that he was self-centered jerk and had no respect for other people. For example, the night when 端王’s troop killed all the outlaws, when 端王 found out that 长风 met 唐悦 after slept with himself, he insulted 长风 in front of the soldiers and called him a "slut". I do believe that anybody who is capable of doing this to his loved one (seeter said 端王 fell for 长风 at first sight") has defect in the character and should not be trusted.

Then, suddenly in the third section, 端王 became soooo amiable that I can not even tell him from 唐悦. How come he changed so much?  i didn’t find any answer in the story (maybe he felt the competition and suddenly realized he was in love?).

So all in all, my feeling is that instead of further developing the 端王 character, the author just merged 端王 and 唐悦 into this "engineered" "super" 端王 for 长风. I guess it satisfied both the author and the readers. But without all the conflicts the author introduced in the beginning, the characters per se and their interactions are
just not as exciting any more. But I guess the story will still be good.