"I've heard about you. They say you're good at what you do. And even better at keeping secrets. The Avatar's alive. I want you to find him. And end him."
— Zuko to Combustion Man when hiring him to assassinate the Avatar.
Combustion Man, given his nickname by Sokka, was a firebending assassin and a silent bounty hunter hired by PrinceZuko to track down and eliminate AvatarAang. Following Team Avatar through the Fire Nation, he terrorized them with his unique firebending abilities which allowed him to project and detonate large explosions at will from his third eye tattoo.
After three almost successful attempts on Aang's life, Combustion Man tracked Team Avatar down at the Western Air Temple. Unwilling to let the Avatar escape again, the assassin overcame all defenses, causing enormous destruction in the process. However, his third eye was hit during the ferocious battle and he unintentionally unleashed a massive point-blank explosion that killed him.
This Fire Nation assassin discovered his ability when he was a young child, but was initially unable to control it, and accidentally blew his right arm and leg off, which he replaced with his trademark metal prosthetic limbs. He then went on to acquire a formidable reputation in a series of very quick Agni Kai. Huge, silent, willing to do any dirty job with no questions asked, and driven to complete his assignments, he was a formidable opponent with a reputation for being "good at what [he does]" and "even better at keeping secrets".
Combustion Man was hired by Zuko to kill Aang, since the Prince believed there was a chance that the Avatar might have survived Azula's attack at Ba Sing Se, an outcome which would jeopardize the new-found respect Ozai had for him. This news drove the firebending assassin to utilize any means possible in eliminating such a potential threat.
Professional and diligent, the Combustion Man eliminated or intercepted any evidence that could compromise his secrecy. When Aang was spotted by two Fire Nation soldiers, the assassin's raven eagle intercepted the soldiers' messenger hawk, enabling Combustion Man to read and subsequently destroy the message. That night, he stealthily approached Aang and his friends' campsite, but his metallic footsteps were detected by Toph. Eschewing stealth, Combustion Man attacked, his powerful bolts countered both Katara's waterbending and Toph's earthbending, forcing them to take cover. He followed Aang as the Avatar led him away from his friends. Following a running battle, Combustion Man's attacks were countered by Aang's airbending and earthbending, and he eventually had to halt his pursuit as the Avatar escaped on Appa with the rest of the group.
In his second attempt, the Combustion Man operated more subtly by setting up a trap in Fire Fountain City via a wanted poster to capture Katara and Toph. He locked them in a wooden cell, depriving them both of earth and water to bend, and used them as nothing more than bait to lure in Aang, which proved successful. After Katara inventively used her sweat to waterbend and escape, the two girls arrived just in time to help Aang and Sokka, who had only narrowly avoided the ambush because Aang heard the assassin inhaling. Katara momentarily hampered his assassination attempt by freezing his head in a block of ice, allowing the group to escape. Toph launched a boulder at him to cover the group's escape, prompting him to explode it. As the rock exploded, a single pebble flew off of the rock and struck him directly on his third eye tattoo, blocking his chi. He got up and attempted to shoot another explosion in the group's direction, only to find his ability hampered. The air around him detonated, sending him flying against a nearby wall, enabling the group to escape. He was visibly angered when he saw his prey escape.
It was during this attack that Sokka stated that "Sparky Sparky Boom Boom Man" was an unfitting name for the assassin and dubbed him "Combustion Man" instead.
After he had traced them at a train station, Combustion Man next targeted Aang while he and Sokka were accompanying a little girl name Sho on a train to her grandmother's house. During the train ride, the assassin attacked the Avatar, preventing his escape by threatening the lives of the other passengers. The explosions caused the train to go faster and knocked out the engineer. After a short hand-to-hand confrontation, Aang convinced Combustion Man to face him atop the train, giving Sokka time to fix the engine. After Sokka stopped the train, Aang used water from a nearby lake to waterbend Combustion Man into the water below.
Combustion Man managed to locate the group during their stay at the Western Air Temple, though Zuko interfered with his surprise attack and ordered him cease going after the Avatar. Having roughly shoved the prince aside and launched another attach, he was threatened by Zuko that he would not receive any payment, an offer that quickly changed to the promise of double payment when he grabbed hold of the young firebender's shirt to hold him off. Combustion Man, however, ignored both offers, appearing to attack for reasons other than money. Meanwhile, Zuko's antics proved to be a useful distraction for the group, who used the time to take cover. When Combustion Man resorted to blowing up pylons supporting the temple, Sokka took aim and used his trademark boomerang to strike Combustion Man square on the forehead, briefly stunning him and blocking his chi. He ignored it and tried to firebend again anyway, causing a massive point-blank explosion which killed him. His metal claw was seen falling into the misty abyss.
Combustion Man's abilities reflected his given moniker, and he was able to trigger explosive detonations through his unique style of firebending, due to an extremely overdeveloped third eye. He was capable of normal firebending, as he burnt a stolen message without forming an energy bolt, but he always relied on his combustive firebending during combat. He channeled chi energy from his stomach, and then focused and fired it from his third eye, through a tattoo on his forehead. This energy created thin transparent energy bolts that cracked like firecrackers as they traveled and then exploded violently on impact with a surface. This ability was mentally driven, requiring only inhalation and focus on his part, making his fighting style much less dynamic than standard firebending, and could be used at great ranges with considerable accuracy. A single energy bolt was very powerful and could disintegrate large boulders or evaporate entire bodies of water with ease. The true degree of his power and skill was considerable, and in almost all encounters he overpowered everything Aang's group attacked him with.
In addition to his unique talents, his enormous size allowed him to possess considerable physical strength, easily overpowering Zuko with only one hand even when looking the other way, and his metal prosthetics made dangerous weapons. Despite his huge frame and two metal limbs, he was surprisingly agile, using his clawed metal hand and foot as a grapple or to break the force of a fall.
His durability and quick thinking enabled him to charge through Aang's tornadoes unfazed, and block Katara's "icicle-striking" technique by shielding himself with his metal arm and leg. It also empowered him to fire prolonged blasts, as seen when he fired an extended blast at Zuko's fire shield to push him backwards. He also proved to be quite intelligent and a skilled tracker, such as when he teamed up with an authority of Fire Fountain City to capture Katara, who was expecting to get a reward for ratting out Toph.
Combustion Man showed no physical weaknesses when being attacked, and was usually impossible to get close to, as he was always shooting explosive bolts, and his enemies were usually pinned down and running in the opposite direction. Ironically, his only shown weakness involved his greatest weapon. Combustion Man was shown twice to be both disabled and stunned when hit in his third eye, even when hit by only a pebble. Even more so, it caused his bolts to backfire, the chi energy in the blast causing an explosion due to its inability to leave his body. This weakness was first caused by a pebble flung from an exploded boulder lobbed by Toph, allowing Team Avatar to get away while Combustion Man was stunned. The second time occurred at the Western Air Temple when Sokka used his boomerang's arcing trajectory to attack Combustion Man from behind cover, and he unknowingly struck him in the forehead. This caused Combustion Man's chi to be blocked and caused a fatal backfire when he tried to attack, destroying a large portion of the temple where he was standing. His metal arm was seen falling from the smoke, and he died in the explosion.
Combustion Man's tattoo of a Third Eye is an exact replica of the Third Eye of the Hindu God Shiva, who is associated with the cycle of destruction, transformation and rebirth. Shiva is often depicted with a third eye, which when opened, destroys anyone and anything before him. Shiva is also associated to the Vedic god of fire, Agni.
A rumor said that Combustion Man was a Fire Nation soldier injured in battle, who was later healed using experimental techniques and those experimental techniques gave him the ability to firebend using his mind.
Combustion Man was never seen or heard speaking save for growls of pain and annoyance, and his real name was never revealed. Although Zuko appears to know his real name, he never stated it. This is confirmed by Zuko saying 'Well, that's not his name, but-' before being cut-off by Sokka.
Combustion Man bore a resemblance to the Marvel Comics character Luke Cage, who obtained his powers after an experimental procedure.
The creators explained in the DVD commentary for "The Western Air Temple" that Combustion Man continued to attack the group because he figured Fire Lord Ozai would be grateful for the elimination of the Avatar, even if Zuko was not going to pay him.
Combustion Man's third eye tattoo was located right where the sixth chakra (Ajna) is, at the center of the forehead.
When encountering Combustion Man, Sokka referred to him as "Sparky Sparky Boom Man", though he agreed with everyone else that the name did not quite do the overwhelming firebender justice and settled on the moniker "Combustion Man", which was immediately adopted. Aang was the only other companion shown to call the assassin "Sparky Sparky Boom Man" when he announced his arrival.
Combustion Man's leg was apparently a fully-functional metal prosthesis. He was the only character shown to use such a device.
The first time Combustion Man attacked Aang and his friends, he fought Aang in a remote field with many tall spires. Aang would later duel Fire Lord Ozai in an area with similar terrain in the Earth Kingdom.
His weakness of being struck in the forehead is similar to the Bible tale of Goliath, an approximately ten-foot tall giant who was killed upon receiving a blow to the forehead from one small stone.
Combustion Man served as the secondary villain in Book Three, a role similar to that of Admiral Zhao and Long Feng in Book One and Book Two, respectively. These three antagonist were all introduced and defeated in their respective book, though Combustion Man had the least screen time out of them.