SPOILER: Everything is just his wish. Before Inseop died in the main story, he wrote a letter to the FL, and everything we’re reading is actually what he wished would have happened.
He imagined a world where he had a chance to be with her, if their roles were reversed. He believed that if he were in her place, he would have accepted and loved her no matter what… even if she was a murderer who ended up killing him

No, she’s not an angel, bro, RUN....
I just saw the last chapter of the side story, and I’m disheartened. You think the artist destroyed us in the main story? She practically nuked us with the ending of the side story