Winx Club: Season 2, Episode 24

2 - 24: Desperately Seeking Bloom (aka Darkar's Prisoner)

The final battle begins, it's all or nothing. With Flora, Timmy, Riven, Musa ,Stella fighting the witches and Brandon, Sky, and Layla trying to find Princess Amentia for help, Bloom is being turned evil by Lord Darkar with the help of Avalon (The Imposter)