Is a Muslim's utterance of the term "gods of fire" – found in anime – considered an act of disbelief (kufr), even if they do not believe in their existence, and is it permissible to write this term for the purpose of inquiry?

It is impermissible to watch movies that contain scenes of disbelief (kufr). However, watching them or recounting their disbelief, without believing in it, does not constitute disbelief. It is permissible to recount sayings of disbelief for a legitimate purpose, such as inquiring about their ruling or refuting them.