The most mysterious of all the members to have passed through the Kiss ranks over the years would have to be short-lived guitarist Mark St. John. Although he appeared on only one album with Kiss, 1984's Animalize, it remains Kiss' best-selling release from their non-makeup era (and helped restore the band's reputation with the worldwide heavy metal faithful). Born Mark Norton on February 7, 1956, in Hollywood, CA, little is known about his early years -- although he taught guitar prior to his joining Kiss once Vinnie Vincent left in early 1984. Rumor has it that guitar-maker Grover Jackson recommended Norton to Kiss when Gene Simmons and Paul Stanley inquired about up-and-coming talent.

While he didn't have much to do in the songwriting department, his highly technical six-string skills helped ignite the album, spawning the popular MTV video "Heaven's on Fire" (the only Kiss clip in which Mark appeared). With his name changed to Mark St. John, the new lineup set out on a European tour in the fall of 1984 as Animalize broke into the U.S. Top 20. Although this should have been a blissful time for the new guitarist, he never quite saw eye to eye with the other members and, worse, a medical condition began to hamper his playing. Bouts of stress and unhappiness brought on arthritis attacks in his hands, preventing him from playing -- friend of the band Bruce Kulick had to substitute for St. John throughout the tour. Although St. John played a few shows, by year's end St. John was out of the band and Kulick was in.

Shortly after exiting Kiss, St. John formed a glam metal band, White Tiger, which issued a 1986 self-titled debut independently but sunk from sight soon after. Little was heard from St. John after the demise of White Tiger (although he joined forces with ex-Kiss drummer Peter Criss for a short time), until he appeared at Kiss conventions in the 1990s. In 1999, he issued his first true solo album, the limited-edition Mark St. John Project EP. Sadly, on April 5, 2007, St. John died of a brain hemorrhage. ~ Greg Prato, Rovi