B1-268 was an OOM Command Battle Droid who was a part of the Separatist Droid Army during the Clone Wars stationed on Agamar.
Near the war's end, Supreme Chancellor Sheev Palpatine issued Order 66, which branded the Force-wielding Jedi of the Republic as traitors and resulted in the destruction of the Jedi Order. Palpatine's new apprentice, Darth Vader, slaughtered the remaining Separatist leaders in their compound on Mustafar. Vader contacted Palpatine, who instructed him to send a transmission ordering that all remaining battle droids be deactivated. Kalani, a Super Tactical Droid who served as a general in the Droid Army and was B1-268's commander, received the message on Agamar, however he assumed it was a trick by the Republic and did not shut down his forces.
Rebels on Agamar
With the Clone War over and the Separatist Alliance dissolved, B1-268 and his fellow droids resided in the remains of a downed Separatist Supply Ship on Agamar. Seventeen years after the end of the war, members of the Ghost Crew entered the supply ship in search of munitions. After locating the ship's munitions depot, the rebels were caught in a ray shield and quickly surrounded by B1-268 and five B1 Battle Droids. B1-268, believing the intruders were a part of the Galactic Republic, instructed his troops to prepare to shoot them, however he received new orders saying that the invaders were to instead be brought to the command center. B1-268 stunned them and had his droids drag the prisoners back to the center.
After bringing the rebels to the command center, B1-268 reported in with Kalani, who congratulated the droid on his efforts. Kalani spoke with the prisoners, two of whom were Jedi, one of whom was a Clone Captain, and one of whom was a Lasat guardsman. Kalani, wishing to end the Clone Wars once and for all with a Separatist victory, proposed that one last battle take place in which his forces hold the Lasat hostage while the Jedi and Clone battled his droids to rescue him. Facing the threat of termination if they did not comply, they accepted the tactical droid's terms and left the ship while Kalani's forces moved into position. After defeating the first wave of droids and making their way to the hangar, the rebels were caught off guard by Droidekas from the catwalk above and forced to take cover. While the rebels devised a plan to defeat the droids, B1-268 moved in on their position along with several B1 Battle Droids. The rebels managed to initiate their plan, however: one of the Jedi, Ezra Bridger, used the Force to ram a crane into the catwalk, causing the Droidekas to fall down onto B1-268's forces down below. B1-268 managed to avoid being crushed, however, and the rebels passed him by as they continued making their way to the command center.
The rebels secured the command center, thus ending the battle. However, the Empire had intercepted a distress signal transmitted by C1-10P, who avoided capture, and had responded by sending soldiers to Agamar. Kalani ordered B1-268 to investigate, and the droid approached the incoming shuttles along with three other battle droids. B1-268 greeted the troopers, informing them that he was sent to ascertain what the Empire was doing on the planet. His words fell on deaf ears, however, and both he and his fellow droids were blasted by the Stormtroopers.