OKAY EXPLANATION FOR EVERYONE THAT IS CONFUSED. (don't get mad at me bc i already forgot most names)
FL is not actually from 'our' world, she is actually from the world of the 'novel'. In fact, the 'novel' she created in 'our' world, is actually just her remembering her own, real world. Basically, the FL is originally from the world of the novel.
She was a g** that loved humans, and because of her love for humans she was taken advantage of and bad things happened. Due to this, the other gods got rid of her and basically split her in half. Her colder half would continue to rule in the gods world as her and the part of her that was more timid and loved humans would be befallen the fate of reincarnating hundreds of times, along with fragments of her soul being scattered around the empire.
One of these many reincarnations was her form at the beginning of the story, Yoon enul (is that the name?).
Killian's suffering all came from her, but it all came from her colder side that had been ruling as her in the realm of gods. After having been awakened by that guy who came to kill her and her family, she went back to the realm of the gods. Then she came back to Killian, a month later. Now we are here.
Any questions?