I’m mostly going off of vibe here. (Note: By ‘Supernatural’ I mean things like ghosts.) Characters who believe in the Supernatural: Loki, Thor, Everyone on Asgard, Peter Parker, Gamora, Hulk, Bucky, T’challa, Scott, Wanda, Marc Spector, Steven Grant, Jake Lockley, Groot, Mantis, Darcy Lewis, Drax, Ned Leeds, Eddie Brock, Wade Wilson, Wong
Characters who are undecided on the Supernatural: Vision, Bruce Banner, Steve, Natasha, Clint, Pietro, Rocket, Sam Wilson, James Rhodes, Carol Danvers, Nick Fury, Jane Foster, Phil Coulson, Yelena, MJ, Venom, Stephen Strange
Characters who don’t believe in the Supernatural: Tony Stark, Hank Pym, Peter Quill, Nebula, Peggy Carter, Shuri?,