Spoilers....
The previous saint gave her power to Leticia's Mather because she would be the one giving birth to the next saint. So the powers were supposed to go to her daughter after her birth, but the darkness (the main villian here) promised her that there is a way to be the Saint. The wings only 4 are real wings 3 are placed by the darkness. All 4 of them will go by Leticia's side slowly as now they are brainwashed.
Ml's brother is dead but the darkness will use him as a puppet. Julius was one of the wings and he had the power to see the future, he saw that if he dies there is a happy future for the rest of them. He was the one that turned back the time too. In the end ml and his brother will meet in the land of the dragon and the dragon will tell ml that he can grand him a wish. Ml will ask for Julius to be back and as he is a wing is possible so he will be back alive.
Fl's mother will be killed by the darkness.
Ml will have a dream with his past life.
The dragon and some other spirits will lock the darkness away.
Fl's brother has been long time now dead and is used by darkness.
Ml mother has the same power with Julius and for that reason she looks abit out of the ordinary.
I don't remember anything else..
I think the 'saintess' knows that leticia is the real saintess bc from what i remember she blames leticia for the weakening of her powers and maybe the reason why she keeps her hidden is bc shes afraid that the wings will realize that leticia is the real saintess but idk