I went with the theme 'Fightober' for Inktober 2018 - fighting game characters, primarily from the genre's golden age of the early 90's. Though I've never been good at these games, I'm a fan of the genre having grown up on kung-fu movies and just living in Japan at the time of the fighting game wave.
All of the drawings were done on 2.5" x 3.5" sketch cards / artist trading cards. I also used this Inktober as an opportunity to learn how to color with artist markers.