"Every ounce of my being will be directed to the destruction of you and your pathetic planet!"—Sendak to Shiro
Commander Sendak was one of Zarkon's most trusted and loyal commanders. When Sendak was stranded on planet Arus, he was trusted to take down the Castle of Lions from the inside, which he almost managed to do, had it not been for Pidge's untimely exit. Shiro ejected him out into space while in a cryogenic pod. There he waited until after Zarkon's death where he was freed by Acxa, Ezor, and Zethrid under Haggar's orders.
After Lotor became the empire's new emperor, he began Fire of Purification, a group of Galra that believe that the Altean-Galra prince shouldn't be their leader, and that the honor should be given to Sendak. He then led his own fleet, planning to take down Voltron.
After the disappearance of Voltron, he led an invasion of Earth that lasted 3 years until his forces were defeated by the Galaxy Garrison and the Paladins. He was then killed by Keith after he fought and defeated Shiro. His death brought an end to the invasion.
At some point, Sendak was stranded on the planet of Arus, and was given a mission by Zarkon to destroy the Castle of Lions. He defeated Shiro in single combat, and hacked into the Castles controls, corrupting the data of King Alfor, forcing Allura to destroy her fathers memoreys, erasing him for good. Sendak was then stopped, thanks to intervention from Pidge. Shiro then ejected Sendak out into space in a cryogenic pod.
Sendak was later collected by Acxa, Ezor and Zethrid on the orders of Haggar after the death of Zarkon. After he learned that Lotor was in line for the throne, Sendak formed The Fire of Purification, so he could take the throne, but truly, he was just being used by Haggar.
He later fought in the Kral Zera, as he hoped to take the throne. After killing a contender, he fought a violent battle against Lotor, until Shiro arrived with the Black Lion and attacked him. He then declared to the other Galra that Lotor had sold them all out to Voltron. Haggar then left him behind.
Later, he led his own fleet on a full attack on Earth, as a way to get the paladins to hand over the Lions. The Humans and Galaxy Garrison fought back with hybrid technology after their Basic fighters were easily taken out. Four years later, the paladins returned with their lions to repel Sendak's invasion. Voltron planned to destroy Sendak's Zaiforge Cannons, yet Admiral Sanda made a deal with Sendak, telling him the plan and getting him the lions in exchange for him to leave earth with his fleet. Sendak then double crossed Sanda, locking her up with the Paladins. They later escaped, but Sanda was killed in the process.
Shiro fought Sendak in a final battle as his flagship fell from orbit, fighting each other with their bionic arms. After a long fight, the ship crashed, and Shiro was thrown on the ground. Sendak stood over him, ready to kill his old enemy, when the Black Lion arrived and Keith leapt out, his sword activated, and slashed through Sendak's chest. Sendak then fell, finally dead.
He was an extremely sadistic and powerful fighter who is not to be underestimated. His loyalty to Zarkon and adherence to the military hierarchy was without question and only obeys the commands given to him. He was a model soldier and citizen of the Galra Empire. He was also skilled in psychological warfare and military strategy, particularly by exploiting the weakness of people valuing others' lives.
When Sendak fought Shiro in the Castle of the Lions, he said "Too bad you didn't get the latest model", referring, of course, to Shiro's Galra arm. From this, we can infer that Sendak underwent the same procedure to remove his left arm, and have a robotic lengthening one in its place. Of course, as a commander, Sendak received the most upgraded version, allowing him to defeat Shiro in a melee fight.
One of Sendak's quotes was the following: "Nothing will stop me but victory or death." Sendak is the military leader who will fight on at the cost of all his men, because He was loyal to Emperor Zarkon and will do what he commands without question. He showed extreme hatred towards Shiro and Voltron when he attacked Earth.
His fighting style relies primarily on the use of his cybernetic left arm and its energy tether and terrifying piercing claws. However, without it he's incredibly vulnerable and can be taken down with relative ease.
He is also athletic, able to dodge and move around quickly to evade attacks. This is despite his large size, wherein he towers over normal humans at approximately 8 feet.
- Sendak is the new incarnation of Commander Yurak (whose original name in GoLion was "Sadak"). This is notably seen with his big feline ears, along with a single bright glowing yellow eye, and the bright red cybernetic eye. The most notable difference in his appearance is Sendak's cybernetic arm is far more prominent then Yurak's prosthetic, and that it has switched sides (now on his left rather than the right).
- He was killed by Keith.
- When Shiro gets a new arm, it is similar to Sendak's as the lower part is floating.
- Sendak is far taller than an average Galra.