I enjoy this kind of story and even the super cheesy romance was pretty cute. There was so many cute moments that I fell in love with their story. I loved Lee Dong Wook a LOT. His characterization and acting was amazing.
The story started off showing how amazing the FL was and honestly that hooked me in along with the cool ML and the different characters around him. And then-
It went a little downhill.
Somehow the FL, very plot conveniently, became a damsel and then a partial villain which came off a little weird (maybe it was just bad acting) Though it was a pretty good plot twist when it all started. The story became even more cheesy to fill up the waiting time and the FL became super dramatic and I could barely see that girl from the first few episodes. But it was still explainable and also kind of sweet, I spent the last two episodes crying and it made every thing before seem like it was worth it.
But then, the ending.
The ending was a mess.
I understood that he was brought back in his previous state- hence the powers- with the lifetime given to him by his brother. And it was pretty sweet.
But the brother sacrificing himself was predicted, but it was very unsatisfactory end.
Personally, I would have rather have the FL die and then have them both reincarnate later at the same time so they could meet again in their next life.

Overall, It was a wonderful show, with quite a few amazing characters, but it did the FL wrong. It did the ending wrong.
But god, was it excellent.