Little is known of the early years of the martial arts prodigy known as Junzo Muto, what is known is that he showed a natural affinity for the martial arts in all its forms from a very young age. Whether it was his genius or his child-like innocence which brought him to the attention of family friend Hiromitsu is unknown but unbeknownst to him, his parents were killed by Hiromitsu who recruited him in the service of a splinter cell of the world class assassin guild known as The Hand
As the years progressed, he blossomed into a cold and ruthless assassin who learned martial arts quickly and developed an appetite for power second only to his mentor Hiromitsu. He soon surpassed his sensei and even those with more combat experience than himself; soon he became undisputed leader of The Hand. Under the guidance of Hiromitsu, he gained insight on the mystical city of K'un-L'un and their warrior Daniel Rand, the Iron Fist.
His ambitions came to fruition when he decided to gain the power he so desired by placing all the players on the field. The first signal to the world that The Hand had a new leader was when he had martial artist Masahiko assassinated. Incidentally, this was one of the sensei’s of the New Warriors leader Night Thrasher. By the time Night Thrasher realized The Hand was behind the death, he discovered that the Steel Serpent had been defeated in battle by The Hand's new leader and what power the Serpent had was stolen by the victor. Impressed by the power he had obtained, he sent The Hand to locate Iron Fist. The Hand swiftly retrieved Danny Rand, who was then defeated by Junzo in single combat, brimming with power; he was prevented from killing when the New Warriors arrived. He engaged Night Thrasher and his team in combat and would have won if the New Warriors had not retrieved and beat a hasty retreat. Impressed by his defeat of his adversaries, he ordered his uncle Hiromitsu and The Hand to call him “Iron Fist”
Junzo Muto - The Iron Fist
After his high profile battle with Steel Serpent, Iron Fist and the New Warriors, he laid low and went about mastering his new abilities under Hiromitsu’s watchful eyes. At a hideout beneath the , Junzo met his cadre of the hand and promised them that he planned to conquer K'un-L'un and with that move, The Hand from the shadows and into the light and thus be feared everywhere. As part of his plan to conquer K'un-L'un, The Hand captured Misty Knight, Iron Fist's then-girlfriend. Misty Knight managed to best two of her ninja captors, only to enrage the young Junzo who ripped out her right arm. Showing a cruel streak not shown before he reminded Misty that he didn’t need her alive in order for his plan to work. Hiromitsu interrupted however before he could torture Misty anymore to inform him that their plan was going perfectly as Iron Fist had arrived in Tokyo and thus K'un-L'un would start appearing there and they would soon have an entire fortress at their disposal from which they could conquer the world.
When the city started appearing in , The Hall of Ancestors was the first to arrive. Junzo and Hiromitsu made their way to the Great Hall, where Junzo introduced himself to Yü-Ti and the Dragon Kings. With Hiromitsu’s help, they then took control of the Dragon Kings and imprisoned Yü-Ti. The Hand then imprisoned Rand, who demanded to know what had become of Misty Knight; when Junzo cruelly explained how he ripped her arm out, Danny attacked him, only to be defeated. Yü-Ti then revealed how Hiromitsu had murdered his parents; Junzo then killed his uncle and took his powers of sorcery from his corpse.
He then met with Misty in her own cell. Ever defiant, Misty attacked him again, but was easily repelled. He continued to taunt Ms. Knight as her usefulness had expired now that he had Danny in his possession. His celebrations were short lived as the superheroes Iron Man, Luke Cage and Psylocke had made an attack on his forces; thinking them a considerable threat, he unleashed the Dragon Kings on them. Unbeknown-st to him however was that Wolverine had infiltrated his fortress and freed Iron Fist in the ensuing chaos. By the time he joined the fray, Wolverine and Iron Fist were on their way to the battlefield via the sewers.
During the battle, he was challenged by Luke Cage, Iron Fist’s best friend. All of Cage’s strength was for naught however as he was dispatched with relative ease by the new lord of K'un-L'un. The Dragon Kings meanwhile kept both Psylocke and Iron Man busy, it was at this point that Wolverine and Iron Fist joined the fray. At the same time, S.H.I.E.L.D., Sunfire and Captain America arrived on the scene; this was little too late however as was gone and K'un-L'un was now the dominant city, thus all technology ceased working. Wolverine then tried to dispatch Junzo, who used his new sorcerer power to control the elements and take down Wolverine. At the same time, The Hand and the Dragon Kings gave the heroes more than they could handle. In a last desperate bid to save K'un-L'un and his own hide Yü-Ti plunged his blade in Iron Fist’s chest as he believed that the only way to make K'un-L'un disappear would be to stop ’s heart, since the city was connected to his life line. With Danny apparently dead, returned to normal and most displeased with the sudden turn of events, Junzo and his assassins made a quick getaway with teleporting via sorcery.
With Junzo’s departure, the Dragon Kings returned to their normal states, free of his control and Danny was returned to life via the very potent magic of K'un-L'un. Junzo has been in hiding since and it’s unknown if Iron Fist’s returned powers have had any effect on his own abilities.
Powers and abilities
The only ability Junzo has shown as being inherent is absorption. In his meetings with Iron fist, Steel Serpent and Hiromitsu, he easily stole their power through absorption. It was never revealed whether this was something he learnt, but it seems to be his only natural power. He is also exceptionally fast; his speed easily surpasses Danny Rand as commented by his uncle Yü-Ti.
After stealing the power of the Iron Fist, he gained the ability to summon and focus his chi (or natural energy) and enhance his natural abilities to extraordinary levels. His strength, speed, stamina, durability, agility, and reflexes and senses can all be astronomically intensified, making his already formidable martial arts skills even more so. The ultimate expression of this focus is the ability to concentrate his body's natural energies into his hand, manifesting as a supernatural glow around his clenched fist, making his fist "like unto a thing of iron." So concentrated, this "iron fist" can smash into its target with superhuman hardness and impact, while his hand becomes impervious to pain and injury. However, the feat of summoning the power required left Rand physically and mentally drained, but Junzo was able to use this ability for extended periods of time and even repeatedly.
Other applications of the Iron Fist power include the ability to focus chi energy inward to heal oneself or outward to heal others of injury, as well as being able to telepathically fuse his consciousness temporarily with another person and meld with that person's mind. While Junzo has not been seen using these abilities, they are within his power.
Other users of the Iron Fist have demonstrated applications including hypnosis and channeling his chi energy into projectile weapons to increase their destructive capacity, enhanced resistance to injury, including resilience to poison gas, a greatly slowed aging process and even invulnerability.
Even without the Iron Fist, Junzo is a world class master martial artist, having defeated Iron Fist at all of their meetings as well as Night Thrasher and Steel Serpent, he is easily one of the most skilled practitioners of unarmed combat in the Marvel Universe.
By killing his uncle Hiromitsu, he has gained magical abilities of teleportation and elemental control.