I’m in the process of helping someone come up with lore and I was wondering if there was a website to help with suffixes related to lore and mythology. Things like adding ist, kin, age, folk, etc to try and make new words for beings or creatures.

Just curiosity as I idly work through details on a project that has a larger "opening" cast than usual. I have a lot of ways I come up with characters and flesh them out (just write them, make them in dress-up games and the like, build them up in daydreams, etc.), but I'm curious about other people's methods.

So, how do you flesh out characters?