During the Clone Wars, separatist scientists found the remains of an HK-Series droid on Mustafar. They built multiple droid designs off of it. Including Commando droids, and more HK series runs. The final of which, was the HK-99 series. During the production phase of the HK-99s, a team of Republic Clone commandoes snuck into the facility. Their mission was to destroy the factory, they succeeded. The few HK-99s that had been built soon fell into disarray. But, a few that had developed individuality stayed around. Near the end of the Clone Wars, a Jedi general arrived on Mustafar, where the HKs were, and proceeded to kill the Separatist leaders there. The last remaining HK-99 stole a ship and flew away. Since then, HK-99 is currently offering himself out as a bodyguard, to improve himself.

Personal Improvement- HK-99 is dedicated to constantly improving his capabilities, at almost any opportunity.

Obsession-+10-HK-99 is obsessed with improving him self.