Marek is an illustrator and concept artist based in Warsaw, Poland. He has been involved in a variety of projects, working for several prestigious companies including Platige Image, Metropolis Software, Breakpoint, Human Ark and Ars Machina. His works include films, book covers, paper RPGs, card games, board games and of course, video games.
You can find Marek's work on his artstation profile: https://www.artstation.com/artist/banditpencil
Full list of speakers: http://www.promisedland-artfestival.com/2016/speakers.html