Obs Kaj was a Falleen Jedi Padawan (of the female persuasion) who served under Lunis and held the rank of Commander throughout the Clone Wars.
Kaj and Lunis journeyed to Katanos VII to investigate claims of illicit cloning, which they confirmed to be accurate. The miners residing there tried to seize Lunis and his apprentice, employing cortosis-armored gundarks with the intention of delivering them to Count Dooku in exchange for credits.
The two Jedi defended against the attack, and Lunis tried to use the Force to connect with Kaj. However, he was unable to establish a mental connection because she had become so disenchanted with what she perceived as the Jedi Order's duplicity during the Clone Wars, leading her to sever her connection to both the Force and her master. The miners killed Lunis right in front of Obs Kaj's eyes. She managed to flee the miners using one of their nearby pods, and attempted to contact any ships in the vicinity, eventually finding one within range. Regrettably, the vessel belonged to Count Dooku, who ordered his ship to target and destroy the pod, resulting in Kaj's death.