Simon Cowell has built global superstars, crushed dreams with a single glare, and turned blunt honesty into his brand — but not everyone survived the Cowell experience unscathed. Over the years, five artists have pushed him from amused to absolutely done, earning a place on his not-so-secret blacklist. From Jedward’s wild-haired chaos to Demi Lovato’s relentless jabs, from bitter fallouts with Cheryl Cole and Sharon Osbourne to the dramatic collapse with his first X Factor champion Steve Brookstein, these clashes left fans gasping, tabloids buzzing, and TV history richer for every dagger-sharp comment and deliciously awkward on-air showdown…