Boss started off exactly the same as his commando brethren. As his training progressed, he consistently ranked highest in his squad for accuracy and all-around fighting ability. He even managed to break Sergeant Walon Vau's arm in training. It was because of these qualities that Vau appointed him as the leader of Delta Squad.
Boss took command of Delta Squad in the opening stages of the Battle of Geonosis. The group was flown in separately in gunships where Boss immediately set about turning a platoon of droids into scrap metal. Boss met up with his demolitions expert Scorch and the two set about rendezvousing with Fixer and then Sev.
During the closing hours of the battle, the squad was instrumental in ensuring victory for the Republic by eliminating Geonosian lieutenant Sun Fac, destroying an underground jamming device and disabling a droid factory.
After the squad disabled the underground droid factory, the commandos were instructed to retrieve the launch codes from a disabled Confederate Core Ship and to destroy it. On their way to the core ship, the Deltas destroyed an anti aircraft bunker. The squad continued their advancement toward the core ship.
Once inside, the squad split up so they could disable certain functions, with Boss tasked with infiltrating the super battle droid storage racks and disabling most of the stored battle droids. He then continued to rendezvous with the squad so they could retrieve the core ship's launch codes. As they progressed, the ship was sustaining massive damage due to the squad's actions, and was on the verge of destruction. The squad barely managed to retrieve the codes and escape through an LAAT/i. The success of the Deltas was later noticed by an important individual.
After victory was assured on Geonosis, the Deltas were deployed across the galaxy. Boss and his commandos became veterans of many engagements. Midway through the war, Delta Squad was tasked with investigating the assault ship prosecutor, the squad's first base of operations, which had reappeared in the Chaykin Cluster after vanishing while defending Republic trade routes near Corellia two weeks prior.
The squad entered separate parts of the ship, each having been tasked with retrieving the flight data from the ship's data cores. Boss entered through the torpedo bay tasked with retrieving the flight recorder data from the aft data core. While on his way, Scorch was ambushed by scavenger droids and incapacitated. Boss also encountered significant amounts of these droids after witnessing one kill a surviving clone trooper.
Boss encountered several Trandoshans and realized that a small army of them were responsible for the taking of the ship. He managed to get to an overlook position where he could maintain a visual on Sev, who was slicing the datacore's access terminal. After retrieving some of the data, he was ambushed by a scavenger droid, which he destroyed, but was incapacitated by a Trandoshan slaver. Shortly afterward, Boss fell under attack by the Trandoshans, but managed to escape.
Boss retrieved the data from the aft data core, and finished slicing the data from the port core, hoping to gain insight as to how the Trandoshans had managed to take over the ship. Afterward he fought his way to the rendezvous point where he was to meet Fixer. After killing a Trandoshan elite he came to the rendezvous point and was surprised by the site of a battle droid dispenser at the meeting place. After joining with Fixer, the two commandos rescued Sev, who had resisted interrogation. The three then proceed to the detention block to rescue Scorch, who had sliced the core and managed to hide it from the interrogators.
The commandos fought their way to the bridge and destroyed a jamming device that prevented them from communicating with their advisor. The advisor revealed that the Trandoshans planned on selling the ship to the Trade Federation so they could buy battle droids to help them capture Wookiees for the slave trade. He instructed them to destroy the Trandoshan dropship in hangar A, which they managed using Trandoshan rocket turrets. Afterward, a Droid Control Ship arrived, intending to purchase the ship from the now-dead Trandoshans. The squad was forced to fight off droid boarders and disable the hangar force field regulators in the remaining hangars.
Now unable to capture the Prosecutor, the Droid Control Ship opened fire. While the adviser scanned the system for any Republic assistance, Delta Squad fought their way to one of the gunnery stations to return fire. With the help of the Arrestor, the Deltas were able to repel the boarders and destroy the droid control ship.
In the final stages of the war, Boss led the Deltas into combat on Kashyyyk, first to rescue the Wookiee commander Tarfful and escort him back to the Wookie. After landing via LAAT/i, the squad proceeded to a Trandoshan prison compound, where the Trandoshans held Tarfful, as well as numerous other Wookiees. The squad infiltrated the compound after killing the patrols and guards outside, but were ambushed and forced to flee further into the compound. The squad found Tarfful, with the help of some captured Wookiees, but General Grievous was interrogating him at the time. Grievous fled after being spotted, but left two IG-100 Magna Guards to kill Tarfful and the Deltas. Delta-38 and his squad destroyed the droids while ensuring the survival of Tarfful. After the rescue, Boss received orders to sabotage the compound. The squad destroyed the landing pad on an upper level, destroying a Trandoshan dropship in the process, rappelling to the lower levels and destroying another landing pad before they were extracted.
Their transport brought the squad to Kachirho where the Separatist army was making its primary advance. Boss and his squad had to detonate the bridge on which the Separatists were making their advance by placing a charge on the central span of expansion joints, thus causing it to collapse. The squad fought its way to the bridge and planted the charge. The detonation of the charge failed, however, and with no charges that could detonate the bridge the squad instead relied on a Wookiee rocket launcher, which they used to destroy the fuel pipeline beneath the bridge. Afterwards they rendezvoused with Tarfful and secured vital munitions for the Wookiee defense. While securing the munitions, the squad fell under the fire of a joint force of droids, Trandoshans, and Geonosians, but defeated this opposition.
Afterwards, Tarfful instructed an elite bodyguard of his to escort the squad to an elevator that would take them to the level where they could man four rocket turrets and cause intense damage to a Separatist cruiser that was attempting to land on the tree they were in. Unfortunately, the escort died almost instantly due to enemy firing, so Boss and the squad had to get there on their own. When the Separatist cruiser started drawing too much power from the cities main power generators, preventing the cities defenses from firing, the squad was forced to activate backup generators. After their ascent to the upper levels, they proceeded to four rocket turrets, leaving one member of the squad to man each one. With the combined firepower of each turret, they demolished the Cruiser, and attempted to regroup at 38's position. Unfortunately, Sev, the squad's marksman, didn't make it to 38's position, and went missing in action. Only a direct order from Master Yoda convinced him to leave without Sev. Despite the loss of their comrade, the Deltas boarded a gunship and were sent back into combat.
As leader of Republic Commando Delta Squadron RC-1138 AKA "Boss" leads his team with a quiet but strong presence. Of his brigade of clones Boss is perhaps the most clone-like, where as the others of Delta Squad seem to have become very unique in their personalities, Boss seems very rigid and military orientated no matter the situation, suggesting he has pursued very little in the way of a personal life outside his duties in the Clone Army.