In the mid-'90s, no two rock stars struck more fear into the hearts of parents than Trent Reznor and Marilyn Manson. These toxic twins started out having a teacher-student dynamic, with Reznor guiding Manson musically to stardom. But Manson's shock-rock antics soon overshadowed his mentor, who was hard at work for years trying to finish his masterwork "The Fragile." In time, Reznor would come to see Manson as a "dopey clown" while Manson seethed about Reznor literally losing the master recording to his early albums.