umbral frigate
They could add titles for the hunters and have them wear them, something apart from the rank of the demon slayer corps.
The demons could add exclusive clothing that only they can wear.
They could add demonic arts that have appeared in other stories apart from the original manga, such as light novels.
They could make the demonic arts change color depending on how the demons want (obviously with some arts, not all).
Let the combat mode music be different, not always the same.
Let the map have seasons: Winter, summer, spring and autumn.
Winter: It's already in the game.
Summer: The sun damages the demons more and exhausts the players more.
Autumn: It does not contribute anything, simply another ecosystem.
Spring: More shady places for demons and many more trees.
Well, other biomes are seen by the devs.
That the breaths have other VFX when a hybrid possesses them (hunter who became a demon)
These are just a few ideas I have for the game.
modest sand
balmy musk
frigid eagle