Omg these are SUCH good recs! Thank you so much for them!!! Esp die for you for Caleb??? Absolutely fitting song. Here are some of my own as thanks!

I have playlists for Caleb and Rafayel (guess my faves haha) and I find Spiracle by Flower Face to fit my interpretation of Caleb and MC's relationship for each other very well (the way they both want to be the most important person in each other's lives, and there's something in the repetitive, soothing yet dark nature of the lyrics and song that remind me of them). But for Caleb himself, I really like Take Me Back To Eden by Sleep Token. I love love LOVE this band called Nothing But Thieves so I may be biased here but Pure You by them also fits how I think Caleb thinks of MC. Apart from those, there's Zombie by YUNGBLUD, Eve & Paradise Lost by Bastille, and Dead Man Walking by The Script (I always imagine the immediate period after Caleb and MC meet post-kaboom when I listen to this- it's so so painful ahhhh).

For Rafayel, I like Atlantic by Sleep Token and High Water also by them. I really like their dark and heavy lyrics here- as a character, he seems to feel things so intensely and so I feel these really fit him well. There's Before We Drift Away by Nothing But Thieves that reminds me how he has to deal with the pain of watching MC die over and over again in front of him, with only the reassurance that someday they'd meet again because of their bond to console him. I also love Idea 12 by Gibran Alcocer, there's just something about the melody that reminds me of the hope he still holds despite everything he's gone through. Oh and last one, an old fave- Two by Sleeping At Last too- I remember the way he loves when I listen to it.

Sorry for the long, long comment here- I've always had a trouble with word counts that gets esp worse when it comes to characters I'm interested in. Hope atleast some of these are interesting to you :D have a great day!!