This page is about the Duo NetNavi. To see information on his robot counterpart, see Duo.

Duo.EXE (デューオ Dyūo) is a mysterious alien NetNavi from outer space in the Mega Man Battle Network series of video games and the MegaMan NT Warrior (Rockman.EXE) anime. His design is based on Duo of the original Mega Man series.


Duo's personality in both the anime and the games are almost identical.

He is a perfectly neutral figure who goes purely on logic as he judges other beings from their planets, whether the species or race is good or evil, which the latter would end up leading him to destroy the planet, as his primary mission is to destroy all evil in the universe.

In the game, he wished to destroy Earth because its inhabitants were too deep in their darkness and were evil, and even after seeing MegaMan defeat his darkness after Duo drew it out from him, Duo stated that MegaMan hadn't destroyed the darkness, just suppressed it, making him deem humanity still too evil to leave alone.

However, he is not without mercy or reason. When any being, such as Lan and MegaMan, has shown him the possibility of hope for humanity, Duo is likely to spare the planet and give it a test to prove itself, and would return in future times to test humanity again.

Duo never attacks a being unless he is attacked or provoked. This happened in the anime mostly, when he didn't outright destroy Earth in his visit, but ended up leaving behind two probes to observe humanity and see if they were fit to survive. He later attacks when one of his probes, Regal, was defeated after the human had defected from his original purpose and attempted to rebel against Duo, which likely caused him to return and deem humanity to be evil. He did decide to give humanity a second chance after being impressed by Cross Fusion, believing that it could potentially be something that would give humans hope for the future, which could be due to how Cross Fusion requires a bond of trust, something Duo might have considered to be a good quality to be explored.

This, however, was only a small setback, as when Regal had returned and caused a disturbance, and how many humans had used his Asteroid Navis for evil purposes, Duo finally made his move, first killing Regal due to his treachery, and then destroyed the Earth. However, Cross Fusion still made him curious, as he could not understand what it means to have a bond of trust and love, and thus was willing to spare the Earth when Barrel offered to fuse with him, along with Colonel, so that Duo could understand what it means to Cross Fuse with a human.

Game History

Duo was introduced in Mega Man Battle Network 4, at the very end of the game as the final boss. Duo is the operation system for an asteroid-based rocket poised to destroy Earth. The villainous Dr. Regal attempts to control Duo, and the program itself acts as judge of the human race, deeming it evil and unworthy of survival. For this reason, Duo intends to destroy the planet, effectively eradicating the species so that there is not a single trace of evil energy left.

When MegaMan.EXE entered the control system of the asteroid, Duo sensed the Dark Soul inside MegaMan and confronted him as a large head. Duo explained to MegaMan that he exists to destroy all evil beings and explained that while humans were intelligent, they were evil and must be eradicated. Duo even stated that MegaMan was evil before he forced MegaMan DS out of MegaMan's body and had the two face off. Despite MegaMan's victory, Duo explained that MegaMan only managed to suppress his darkness, rather than destroy it, and therefore meant that he is not strong enough to destroy evil. MegaMan refuted saying that everyone has darkness inside them, but they would try to fight it to make sure that it never takes over.

Restating his purpose for creation was to destroy all evil, Duo takes on his battle form, summoning his body, arms, and helmet before he faced off against MegaMan. Despite the odds, MegaMan ultimately emerged victorious, destroying Duo's battle form. Duo was shocked that his battle mode was defeated, but claimed that it was too late to change the asteroid's course and won't be long before it entered Earth's atmosphere. Seeing that MegaMan was still determined to go on, Duo granted passage to MegaMan to the control system. 

However, as Duo surmised, MegaMan was too weak to change the asteroid's course and continued to countdown until they reached Earth's atmosphere and said that MegaMan should just give up. However, much to his surprise, the asteroid's systems could feel much vibrations coming from the Earth's atmosphere. He turned the vibration sensors on and then could hear everyone in the planet shouting out MegaMan's name. Duo did not think that it mattered much before he saw MegaMan suddenly display a great increase in strength, moving the system a bit. Using all their energy, Lan and MegaMan performed a Full Synchro and finally altered the asteroid's course, thus avoiding Earth's destruction from a collision with the asteroid, before the two passed out. 

Duo was impressed by their showing of unity and the power that came from it, before stating that he would one day return, whether it would be decades or even centuries from now. He then gave his farewells to MegaMan and sent him back to Lan. 

Although his story essentially ends at the game's conclusion, he makes anonymous appearances in Mega Man Battle Network 5 and 6, saying that he is watching both Lan and MegaMan and aiding their quest against evil by providing powerful chips that takes after one of his signature attacks. These occur in the Nebula Area and the Graveyard.

Anime History

In the anime, Duo is a godlike entity that was referred to in Axess by Ms. Yuri that had passed by Earth fifteen years before the series and in the process, crashing into a plane and destroying everyone, save for Ms. Yuri and Regal, both of whom were passengers inside. He turns the two into probes to monitor human life, altering their human DNA to make them superior to other humans, then leaves them in the ocean to be found and raised by Dr. Wily. However, both Regal and Ms. Yuri defected from their original purpose and sought to control the world, though Ms. Yuri strays from that as well after regaining her memories of her sister.

When Regal initiates a Dimensional Area that envelops the globe at the end of Axess, Duo is alerted to the chaos and sets off to perform "Earth Erasure." Coming to Earth, he created giant Viruses to materialize in the real world and cause havoc and chaos. However, after Lan Hikari and Chaud Blaze delete the viruses, Duo appears before them and showed them what he had done to his home planet, and declaring that he would do the same to theirs. However, Duo became curious to their forms, being that of human and NetNavi, which is something that he had never encountered before in any other planet that he had come across. After he got an explaination about how Cross Fusion worked, he becomes intrigued by Cross Fusion and decides to spare the world so that it may prove to him that it merits survival. He reverts the damage caused by his advent, then marks thirteen individuals with the Crests of Duo, those chosen specifically for such a purpose. One of his crests he had sent ended up going back in time to Colonel Barrel, instead of staying in the present. Humans would then believe that Duo's comet had passed by, but rather, those with his crests would see that Duo still remained, although some humans were still aware of Duo remaining without his crest.

Afterwards, Duo crashed his comet into the planet, and went back 30 years in time, to when Earth's network society began, and had Slur use the techology to distribute Asteroid Navis to humans of the present time from the Past Tunnel that he created from that. The Asteroid Navis were meant to enhance any human's greed and other negative emotions, and the negative emotions were converted into energy sent to Duo's comet to activate it, by which Duo would then destroy the planet. However, those that had the 13 crests would be able to take control of the comet and stop Earth's destruction. 

Duo wasn't seen again until Lan and the others had discovered the ruins of that held the Crest of Duo, in which they ventured inside and soon activated a digital memory that informed them of Duo's origins, which had sent an energy burst that Duo and Slur recognized, with Duo merely saying Creator.

Lan and the others then learned that Duo was created by an alien race (simply called the Creators by Duo): the extraterrestrials that oversaw this genesis intended for Duo to control their "chaotic" network beyond the boundaries of their home planet, and he was therefore installed into a shuttle that was launched into space, eventually becoming a comet once it reached the outer limits of the atmosphere. Duo, however, defected from his original objective, as he felt that their network was "flawed-evolutioned" and that he would destroy anything that would "harm the Universe" . From his comet, Duo laid waste to the planet, but not before some of its inhabitants escaped on a floating city, eventually landing on Earth during the age of the dinosaurs. It was then that the Creators began researching methods of halting "The Cybernetic God". Eventually, the survivors came across a process similar to Cross Fusion, but were unsuccessful in completing a viable hybrid being, and only their city remained intact by the time it is discovered in Stream, shielded by technology akin to the "Dimensional Areas." However, Slur then moved to the ruins of the Creators and had them destroyed. Whether this was done on Duo's orders is unknown.

Duo's final appearance was at the end of Stream, when Regal entered his comet and used the 13 Crests to take control of the power and technology held inside. However, after seeing this happen, Duo immedaitely interfered, killing Regal as part of the process to "fix" the "flawed-evolutioned Network", and then began Earth's Erasure once more, destroying the planet 30 years ago, but the holders of his crests were able to enter his comet before they were destroyed, making them the only survivors.

Confronting the Cross Fusion team, Duo let out that he had postponed Earth Erasure and granted the 13 Crests to 13 humans so as to see through what kind of power Cross Fusion witheld: the 13 humans were supposed to come into the comet to meet him but they were too late because Earth had already been destroyed. 

He then expressed that because humanity's greed and evil infested the world with the Asteroid Navis, and claimed humanity itself speeded up its end. He also deemed that even Cross Fusion was but the legacy of a "flawed-evolutioned" network civilization, and thus must be destroyed. When he was met with opposition, Duo quickly defeated them all with a single attack, and then stripping them of his crests, rendering the humans unconscious. He then seperated the NetNavis from their humans, and asked them to swear loyalty to him, deeming that while they were from a "flawed-evolutioned" network civilization, they were still excellent NetNavis, and in order to seek a new future for Navis, he wished for them to come with him and escape the shackles of humanity. If not, then he would delete them as well, as unfortunate it may be. 

However, they all refused, willing to be deleted than abandoning their partners, making Duo question why they would do such a thing when they are the source of evil that destroyed their own planet. The Navis explained that humans can learn from their mistakes and grow, change a future of despair into one of hope, how there are kindhearted humans as well, and even if some were bad, they wouldn't abandon them. Unable to understand, Duo asked them why they were so fond of their humans, to which MegaMan.EXE explains that they liked humans, and that Lan was his friend. MegaMan also went to explain how Duo's people had also attempted to find a future for humans and Navis with Cross Fusion as their research, to which Duo asked once more about what Cross Fusion was, showing that despite deeming it from a "flawed-evolutioned" network civilization, Duo still held curiosity over it.

Once more being explained that it was a union between human and Navi, forged from a bond of trust, Duo stated that to a supreme being like himself, their existence was outside of his calculations, and thus had to be deleted. However, Lan and the others woke up, and standing in front of their Navis, refusing to allow Duo to destroy them, mirroring what the Navis had done moments earlier, which again peaked Duo's curiosity to such selfless acts. However, despite being told again that it was because that the humans and Navis were friends, Duo's inability to understand trust and love made him call it something outside of his calculations again.

Left with no other options, Barrel stepped forward and told Duo that he will make Duo understand Cross Fusion, by performing it with Duo, intending to fuse with the Cybernetic God. Lan attempted to stop Barrel, but Duo stopped Lan from interfering, and expressed his interest, asking that if he were to fuse with a lifeform, he would be able to understand Cross Fusion, to which Barrel said that he would. With Colonel also wishing to be with Barrel, Duo took the two, absorbing them into himself, before enveloping everything in a bright light, as Duo seemed to restore Earth once more, perhaps convinced and understanding what it means to Cross Fuse, and having left with Barrel to explore the vast universe.

Because Duo left Earth from 30 years from the past, Duo returned Barrel at some point, after having explored the vast cosmos together. 

Duo is never seen again afterwards, but it is possible that Duo would return just like in the games. 

Also, it was likely from Duo's appearance that had caused a tear in space that allowed Beyondard to connect with Earth in the events of Beast


Duo, compared to and like most final bosses in the BN series from BN4 onwards, has a total of four different forms. However, each form must be fought on different save files, depending on the difficulty selected, and the final version, like with most of the Omega versions, must be unlocked by unlocking all of the 7 special icons on the start menu.

Also, unlike most final bosses and like most of the Navi bosses in Battle Network 4, Duo has a different coloration for his final form. He is also found and fought in the same place where the final story scenario takes place as always for all versions.

  • Duo (2000HP) AKA Duo Version 1 is the default version of the final boss of both versions of BN4, and only on Normal Mode. This version of Duo causes his ring riff to shift up to 5 times during his Stream Laser attack, and is fought in the Control Area in the Meteor Comp 5. The player first must fight a sub boss in the form of Dark MegaMan.EXE, then proceed on to the final battle with Duo himself. During this time with the cutscenes and battles upon entering the Meteor Comp 5, it's not possible to save. Duo here is colored with a shade of white, blue green and red, and stays colored like so for his two next subsequent forms.
  • Duo α (Alpha; 2500HP) AKA Duo Version 2 is the same as the initial version, only he is fought on Hard Mode. The location to battle him is the same, and like with V1 can be fought repeatedly (until Duo Ω is unlocked). There are not much changes to this version other his attacks doing roughly 50-100 more damage than his default version, and his Stream Laser ring shifts positions up to 6 times instead.
  • Duo β (Beta; 3000HP) AKA Duo Version 3 is instead fought on Super Hard Mode. His Stream Laser ring has a total 7 position shifts, and his damage on his attacks is boosted by another 50-100. This version can be fought repeatedly until Duo Ω is unlocked.
  • Duo Ω (Omega; 3500HP) AKA Duo SP is the final form of Duo, this time with a gold, gray, orange and magenta coloration and his moves are boosted by 100-150 damage from his original default version. Once this version is available, it will replace the original version no matter the difficulty, as it is fought in the place of the all other versions upon obtaining the 7 special icons while being able to fight it repeatedly.

Powers and Abilities


The Crest of Duo in the anime.

Duo possesses a variety of extremely potent abilities, many of them manifesting themselves in the form of space-age weaponry. Duo's only weak spot is at his chest cavity when it glows red. As he floats in space with no panels, ground-based attacks can't harm him.

Duo's cannon is meant to be his weakpoint, and despite his panel area's comp, it's possible to Area Grab his visible side of the field.

In the anime, Duo is far more powerful than any other character in the series; his powers are almost godlike, to the point that he can be considered to possess omnipotence.

He possesses the ability to separate Navis and operators from Cross Fusion with a mere thought, allowing them to take on physical bodies while in his comet, as well as creating physical forms of giant Viruses when he first began his attack on Earth for its erasure. He can block attacks by barely moving an inch and defeating various adversaries at once with just a single attack. Another ability he has in the anime is to edit DNA, leaving the subject with supernatural powers like extremely high intelligence (like Dr. Regal) or the ability to survive and heal faster from heavily damaging physical experiences (like Ms. Yuri). He is also able to give certain humans that he had deemed worthy with his crest, which seems to be able to increase the synchro rating for Cross Fusion, and allow them to see his comet, despite how others couldn't, though it seemed like certain humans like Wily and Jasmine's grandfather were still aware of Duo's presence.

Along with that, Duo's presence and influence in the planet caused a temporal distortion, enabling the past and present to become connected thus allowing Barrel and Colonel to enter the future, or ShadeMan to go back into the past. When Regal was controlling his comet, Duo stopped him because the countdown had ended: Duo stole Regal's bodily energy and reduced him to a skeleton.

Duo has also access and knowledge of highly advanced technology, being able to create Asteroid Navis for humans to use, who are superior to normal Navis, along with Dimensional Chips for the humans' PETs that would enable the Asteroid Navi to materialize in the real world, which Slur was sent to give to humans for the test for humans.

The greatest feat of his omnipotence is when he had managed to repair any damage done to the planet as if it never happened. When he first performing Earth's erasure through the summoning of giant viruses, it was a worldwide phenomenon that had destroyed many cities and ships, but after Duo decided to give humans the test, he withdrew his attack, and all the destruction caused was restored. At the very end on the Stream series, he destroyed the Earth completely along with every non-Crest of Duo holders in it. Then, he undid everything after Barrel and Colonel sacrificed themselves to Duo. This could potentially be tied in with his temporal powers, though, but it is unclear.

The extent of his powers and omnipotence is unknown, however, it may be possible that Duo has limits. Regal was completely sure that his worldwide Dimensional Area would be able to protect Earth from Duo, and even attempted to take control of Duo's comet. However, it is likely that Regal had underestimated Duo a great deal in his arrogance.

  • Duo Knuckles: Duo's fists are capable of crushing those that oppose him, and may detach through rocket propulsion to strike his enemies. These attacks are performed from those fists:
    • Meteor Knuckle: Panels flash, and Duo rains his fists down on MegaMan's field, cracking random panels.
    • Justice Fist: Duo smashes a 2x2 fist on MegaMan's field, which cracks the panels in that formation.
    • Big Hook/Gigant Hook: Blows two lightning-fast hooks two columns behind and in front, not cracking panels, but destroy objects and heavily damage enemies.
  • Duo Cannon: Duo uses the epicenter hole to release a variety of following projectile attacks: (This cannon is meant to be his weakpoint in BN4)
    • Destroy Laser: Fires a straight red laser shot on the center row which can fan out via a central ring riff coating the laser at certain points along the spectrum. Pierces Invis if it connects. Each version of Duo adds one extra time the ring riff appears, and it moves along a certain pattern. Duo's first version has the ring move up to 5 times, while up to the final form causes the ring to shift 8 times total.
    • Duo Missile & Duo Yura: Shoots missiles and mines from its chest, occasionally both at once. The missiles home in on MegaMan's row, and the mines travel in a 2x2 wave pattern. The missiles can be shot down, but depending on the version of BN4 and the version of Duo being fought, it's possible to do so with ease, or lack the firepower to do so via the different types of system mechanics available.
  • Anger Impact: Duo releases a wave of energy in an echo effect that resembles his face, cracking MegaMan's two front columns. It's used if Duo is low on HP. This attack was the only one used by Duo in the anime, and it was powerful enough to easily defeat all of the Cross Fusion team. 
  • Crest of Duo: A crest given by Duo to humans in Rockman EXE Stream. People with this crest are able to use Cross Fusion. It first appeared in Episode 2. These Crests allow one to control the guard robots inside the ruins of the Creators. Also, when all 13 of Duo's Crests are together, they allow one to have access to Duo's comet and control it. 

Battle Chips

Duo is an event only chip from Mega Man Battle Network 4.

Justice One (ジャスティスワン) is a Mega Chip from Mega Man Battle Network 5 given by Duo in the Nebula Area.

Meteor Knuckle (メテオナックル) is a Giga Chip that launches punches like meteors.

Big Hook (ギガントフック, Gigant Hook in Japan) is a Giga Chip.

Meteor Knuckle and Big Hook are given anonymously by Duo, each in one of the game versions their appear. In Mega Man Battle Network 5 he gives the chip after MegaMan defeats Chaos Lord. In Mega Man Battle Network 6 he sends the chip via e-mail when MegaMan enters the Graveyard area.

Mega Man Battle Network 4

Secret ChipBN4GChip006Duo 200BC Element Null None

Mega Man Battle Network 5

Mega Chip 17BN5MChip017JustcOne Fist atk on center panel280BC Attribute Break Break
Giga Chip 2
BN5TCGChip002MetrKnuk Meteors bombard from sky100BC Attribute Break Break
Giga Chip 2
BN5TPGChip002BigHook Hook atk 2 sq wide240BC Attribute Break Break

Mega Man Battle Network 6

Giga Chip 2
BN6FGChip002MetrKnuk Meteors bombard from sky100BC Attribute Break Break
Giga Chip 2
BN6GGChip002BigHook Hook atk 2 sq wide240BC Attribute Break Break



  • A Duo Soul was planned to be added to either Mega Man Battle Network 4 or 5 along with a Forte Soul, but there wasn’t enough data on the cartridge. Bass Cross would be added to all versions 5, however.[1]
  • Duo's personality is very different from his classic counterpart, who also wanted to eradicate evil energy, but was notably less extreme in this venture.
  • Duo is the only final boss in the Battle Network series whose Ω form has a new colour scheme (gold instead of white).
  • It is interesting to note that at the end of Mega Man Battle Network 4, Duo says that he will return "decades, perhaps centuries later", which has led to speculation that Duo may appear in the Mega Man Star Force series. When Mega Man Star Force 3 was announced, many fans believed Duo to be Meteor G. This was not the case.
  • The insignia on Duo's arms is similar to that of Mega Man Star Force's icon.
  • Duo's facial design bears a slight resemblance to High Max.

See also



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