I'm not much of a romance fan, but I'll admit even I am totally into enemies to lovers. Villain to love interest is EVEN BETTER, hahaha.
I also love it when a character owns/carries on their person more weapons than is necessary/possible. Why?? We don't even know?
I also love it hyperprepared characters. I don't care who it is, if they have a backup plan for their backup plan's backup plan I LOVE AND SUPPORT THEM.
(While writing this I suddenly realized why I love Artemis Fowl.)