Ossi has nearly 20 years of experience who studied graphic design in Lapland and illustration in Japan before transitioning from commercial advertising and packaging work to illustrating for roleplaying games, including work for Chaosium Inc. He began playing roleplaying games like RuneQuest and Call of Cthulhu in his early teens and now lives in Järvenpää, Finland, with his family while enjoying hobbies that include collecting art books, watching Westerns and samurai films, and continuing to play roleplaying games.