For Cosmic Fish it might not seem obvious at the time (since a lot of things are still being established) but three inspirations drive the plot when I decided to go with the story:
(1) Mental health, personal views/acceptance, and healing (how ghosts change throughout the story is the giveaway here, and it's based on a lot of personal experience/growth)
(2) Picking up and mixing older ideas I really wanted to make in comics from things I enjoyed in books, cartoons, and movies I grew up with. (The designs are based on dreams I've had or things I've drawn without a goal/pure boredom because I wanted designs that stood out or looked off on purpose.)
(3) Commentary on social and personality/identity erasure through powerful groups + some jabs at colonialism here and there (this one might sound too out there, but that one falls into the plot at least 3 more chapters in and anything so far are hints by looking at the backgrounds and the relationship between guardians and ghosts (especially later on)) However, it's not the main driving force which is why it gets third place.