Maybe he can sense that she is the saintess with unlimited light magic...? Or that the dude is destined to be the legendary hero...? I don't know (￣∇￣")
I mean, if the ML has dark magic, it wouldn't be that much of a stretch for him to sense her light magic, especially if she is so powerful. So maybe he wants to get her out of the way so that the hero will fail. And falls in love instead LOL
My theory is that he was the one who was supposed to kidnap her on the day of the break up as she said it was supposed to happen on that day but it didn't.
Spoiler but not really?
He's the demon lord.
But didn’t it say he was the demon lord in the description?
I clearly didn't read it hahaha sorry
I’m so confused as to why the ML is getting interested. What’s so interesting about a break up? How is a break up getting “more and more interesting?” Unless he actually knows the plot of the story, it doesn’t make sense at all.