Slaymaker was a sorcerer based in San Francisco. He was once a young artist who had several wild thoughts and ideas. His problem being materializing them in actual work. He turned to the study of magic in hopes of discovering such a way. He mastered the art of transfiguration, learning how to shape living tissue to whatever form he could think of. Able to even create a small army of demonic-looking servants. Uncertain where he got the living material for that.
When located by the Defenders, Slaymaker was working on his greatest masterpiece: the Panetropic Engine. The Engine consisted of a pyramid of living bodies which would effectively increase his magical powers to reality-shaping levels. He managed to defeat Dr. Druid and Spider-Woman/Julia Cornwall Carpenter and add them to his pyramid. While Slaymaer was distracted with facing Cadaver and USAgent, the two captive heroes took over the Engine from within. An attempt to wrestle back control from them only resulted in the engine exploding. Slaymaker was left in a coma but was happily able to explore his own subconscious while at it.
Slaymaker was created by Tom Brevoort and Bill Wylie in 1994 and first appeared in The Secret Defenders # 20.