Steven Universe Future: Red Diamond

Steven Universe returns home from his trip. Catching up with the Crystal Gems one of them spots a new gem that nobody has ever seen before. Nobody knows who she is or where she comes from, but what was most odd was that on her uniform was a red diamond marking on her clothes. This oddity caused them to grow curious and so they approach to ask who she was in order to uncover her mysterious origins and in implications for all of gem kind.