Cobalt was a soldier and sergeant for a squadron of troops in the Battle of Earth but, much like his siblings Rhinestone and Graphite, defected to the Crystal Gems after the battle. He is usually a fun loving individual but during combat and operations he is very methodical and devious with plans. He usually uses his skills as a commander and battle enthusiast to make traps and ambushes for Corrupted Gems for easy capture of the gems.
Weapon and Powers
His main weapon is a plain wakazashi and katana combination, that of which great samurai use in their battles. He also possesses the ability to scan any area to look for supplies and other pieces of equipment to make a trap or tool of some sort.
As surprising as it may seem, Cobalt is the most serious of his brothers and one person in the Crystal Gems. He takes his responsibilities and jobs very seriously and does them as soon as possible.