FL suffers from incurable toxic selflessness. Her chronic hero syndrome causes "Male Lead" to become a corrupt dragon since she is to busy desperately saving everybody else but him, with zero regards to her mental & emotional well-being and personal safety. This has tragic consequences to her and ML both and she only realizes when it's too late. 11th hour character growth that only gets retconned at 5 minutes to midnight.
"Male Lead" is supposed to be an expressionless and emotionless dragon, but he is so non-existant in the story as an individual; for the second half of the story, he is even completely off screen while "2nd Male Lead" has far better presence/character growth. If you only read the second half and didn't know what happened in the first, you'd think the human prince, who was an antagonist in the first half, is the hero of the story on a road to redemption while the dragon is a background Sauron figure/plot device they only talk about and show in one second scene.
All in all. FL started as selfless fool who MUST save everybody, only to suffer the tragic consequences of her own kind, reckless choices. ML was more of a plot device than an actual character, the smallest of side characters had more character/growth/presence than him. Male Lead is in the story to be a doom device and nothing else. The most interesting was "2nd ML" who as a child suffered tragic losses, was groomed by false friends and was actually a chess piece; he made realistic, mature choices, realized what he did wrong and suffered the real consequences of his own actions without complaint like a true stoic. FL hurls abuse at him with her words while he desperately ties to keep her alive in the second half of the story in order to bring her to "Male Lead" who has gone mad of-screen and is destroying the world. Only when it's too late does she realize where she went wrong and tells him that, if she was ever a dragon herself, she would choose him as her fated partner. In the last moments before FL has to reset the timeline in order to undo the apocalypse brought about by ML , who was made insane by FL's desperation to save everybody, 2nd ML-the only character who had any growth, says "she made her choice to be with the dragon and I want her to be happy forever". Then, FL "fixes" ML with her love, they reset the timeline and in the epilogue, FL and ML are once again selfless and emotionless, all their character progression gone, while 2nd ML is a good king who does everything for his people's benefit, but never marries because his soul remembers the dream of previous timeline where he fell in love with FL on his road to redemption.
Came for inhuman male lead and human female lead romance, was disappointed by lack of progress of their "romance". Stayed for the tragic character of human prince turned fine king.