Black Onyx

Backstory
He has a spiral sword. He was a loyal soldier in the Diamond army, until he saw that Pearl was the one who pretended to be Rose Quartz and pretended to shatter Pink Diamond, he tried to talk to the Diamond authority, but he was just a low-class Onyx and the only male gem in the army, after confronting the Diamonds, they didn't believe him, so he was sent to earth for telling lies, where he was nearly shattered, but he was only corrupted.

Friends
Biggs Jasper, Snowflake Obsidian, and Uranium