Steven Universe: The Movie

Steven Universe sees his past come back to haunt him in the form of a deranged Gem who wants to destroy the Earth. After an introduction from the Diamonds, Steven greets the citizens of the Gem Empire and celebrates the newfound peace, but his past comes back when Spinel, a deranged and cartoonish Gem, appears and poofs the Crystal Gems back into their gem forms. With her memories gone, Spinel is a goofy and happy-go-lucky Gem whose function is to entertain her companion. Steven seeks advice from his friends and they try to raise his spirits, but Spinel's antics cause trouble. As the group tries to find a way to restore Spinel's memories, they discover that she's been using a device to reset the minds of rebellious Gems back to their default state. Steven eventually realizes why his Gem powers have not yet returned and regains them, and in a surprising twist, the Diamonds take Spinel in place of Steven, and she happily goes with them.