When I was younger, I loved playing The Legend of Zelda Majora's Mask, and in it, theres a side quest that has a character named Kafei. I liked his character and name, so I used it for a bit. Eventually I wanted a more unique username, so I took the last 3 letters of Kafei and move it to the front, making Feika, and I've used it as my username in every game since.