Previously on my Steven Universe Fanfiction…

After being cleansed of the Sludge, Obsidian returned to normal life as a Crystal Gem on Earth. Unfortunately, he was still sad about his sister, Onyx, who had disappeared over a hundred years prior. To help, Ruby warped to the Brak System to search for her. Once the Gems found out about this, they went after her and found her with Sapphire, another Crystal Gem who had been sent to keep an eye on the Sludge affecting Planet Zorak. Sapphire told them that Steven was the only one who could stop it. Using his Rose Quartz Bubble Shield, Steven took the Gems to the epicenter of the Sludge, a giant bubble with a glowing object in the center. A few minutes after Steven went into the bubble, he saw the object. It was a cracked Gemstone. He cured it, and the Sludge became Onyx. Obsidian promised to complete her training, but he had some questions about her disappearance. Onyx promised that she would explain what happened.

As we speak, Obsidian trains with Onyx…