Attacked the Crystal Gems because they found a mirror that could show events from the past and didn't know that the thing on the back was a person, broke Greg's leg, attacked Lion and the Crystal Gems...again, tried to drown Steven and Connie, told Homeworld about the existance of Crystal Gems, and willingly fused with Jasper. Even though it was to trap her, she could've said no. They were next to an ocean, and it would've been Garnet, Amethyst, Pearl, Lion, (Steven seemed pretty tired) and possibly Lapis versus Jasper. There was no real reason to fuse with Jasper to win.