My biggest inspirations are almost always pulled from the media I consume. Music, animations, video games, books, comics etc. More often than not I don't realize that I'm inspired by something until I'm halfway through the designing/writing phase.

However lately with writing lore and stories is a more recent thing. By which I mean I only started getting serious with writing in the past 5 years after I started my own original thing detached from existing media. Because of that I've gotten more into story writing, and I pull inspiration from sources like the Cyberpunk genre, cosmic horror, Mobile Suit Gundam, Chappie, Titanfall, Avatar (the blue people movie), Fallout, Last of Us.

I like to have a lot of the content I make grounded in the reality of whatever continuity it takes place in. For example: with my Sonic OC's I base their existence not around Sonic's adventures, but the world the adventures take place in. Most have never even encountered any of the official cast. Most don't have powers, or at the very least they have powers that make sense to their type of character (with exception).

It's difficult for me to explain what I mean, because while I love to write, I struggle to put into words what I envision. If this is too confusing, please feel free to send another question asking something more specific