Steve Raffel

Steve is the artist and level design of Heretic and Hexen titles. He and your brother Brian Raffel founded the Raven Software.

Biography
Steve Raffel founded Raven Software with his brother Brian in 1990. Steve did artwork, level design and game design for many of Raven's early titles (Black Crypt, Heretic, ShadowCaster) and was the Project Director for MageSlayer. Steve did artwork for Soldier of Fortune and assisted in the development of Star Trek: Voyager - Elite Force.

Source
This article incorporates Biography text from the http://www.ravensoft.com/ homepage.