Its not really confusing in the sense that we have questions in need of answers that are not yet given and the story is being told in a non-linear fashion. Thats not everyone's cup of tea but still a matter of personal taste. We see such in movies and books too.
To stab the devil? We all wish to do that, but i assume you'd do it with something cold and sharpish, while i'd do it with natural weaponry
Noobody likes being controlled but in a world where supernatural beings are present and mere humans are not the top of the foodchain, these kinda things can happen whether someone likes it or not. Basically the supernatural being doesn't give a shit whether the mc likes it or not. You'd be doing it on lesser beings, so when you end up being the lesser being...