It’s been bugging me for a while. This is a young adult book from my childhood likely read between 2006 and 2010 from my school library.
It’s a fantasy book and the cover has flames on it with (I think) electric blue writing on it (like literal lightning font).
My very rough description: there’s a group of people traveling between realms (sort of like heaven and hell).
I’m so sorry that’s all I have!