I have also read it! since this promo is for the novel of the same name, some translations of the title is slightly different tho. “Find the one who abandoned me.” I read up to chapter 103, and there isn’t a clear answer for what he did in the first life from what i remember. The FMC is a bit bonkers though, she keeps comparing the ML to the one in her first life, yet this ML isn’t exactly the same one because the memories are different now. The things that happened in her first life didn’t happen in the second, so she brings up memories sometimes that never happened in the current life. The ML DOES love her, and goes along with her sometimes because he wants her to be happy even if she seems delusional sometimes. It has some parts of his pov but only in the current life. So you get his emotions too, like he feels like she doesn’t see him for who he is like she is looking at someone else when she looks at him. Which honestly she does do that often in the novel, it makes you feel bad for the ML sometimes. I don’t think he loved the saintess in the first timeline though, because he seemed so in love with the FMC in both timelines. Also the saintess doesn’t seem evil from the sounds of it, and she just is looking for heros to help defeat the demon that will destroy the world. That is the basic summary of what i remember! You can read it online!

I think there was a misunderstanding and ml wasn't actually able to return for some reason and ofc the mc was a reincarnation? I swear I read this one before