Magical Reality Check Winx Club : Season 1 Episode 10

The girls take a virtual reality game where they are only allowed to take one potion and rely on their Winx for the rest. Bloom is first, and the witches invade the game, knock Kikko in the lava, and steal Bloom's dragon fire. The game is about to blow up and Bloom is still trapped inside. Bloom finds Kikko and they fix the VR chamber and Bloom is found. Then it turns out the witches have no dragon fire.