Double Soul

Dark MegaMan and the Double Souls from Mega Man Battle Network 4.

Double Soul, known in Japan as Soul Unison (ソウルユニゾン, Souru Yunizon), is a term used in the Mega Man Battle Network series of video games and MegaMan NT Warrior anime and manga. It is an ability employed by MegaMan.EXE or any NetNavi to gain added powers and techniques in combat using the powers of an allied NetNavi.

Double Soul was first introduced in the two incarnations of Mega Man Battle Network 4. Out of twelve souls, six were exclusive to either game. It appears once more in both versions of Mega Man Battle Network 5. It replaced MegaMan's Style Change capability of previous iterations, and is itself replaced by the Cross System in Mega Man Battle Network 6.

Double Soul may also have been the basis for the Trans Arm system from Rockman.EXE Legend of Network.

Description

In the closing events of Mega Man Battle Network 3, MegaMan sacrificed himself to save his operator, Lan Hikari, from absorption by the horrific Alpha program revived by Lord Wily. Lan thought his ally and brother to be gone forever, only to be revived using data from his grandfather Tadashi Hikari. His revived state, however, rendered him unable to utilize the powerful Style Change programming option any longer. Hence "Double Soul" was developed as a suitable replacement.

Unlike Style Change, which can be performed by a single NetNavi, Double Soul occurs when a Navi's soul communes with MegaMan. This usually happens after battling against the respective Navi in Battle Network 4, or completing a "Liberation Mission" that occurs after having them join the player's team (excluding ProtoMan/Colonel, which is obtained near the end of the game instead).

Once the player has gone through the Double Soul tutorial, a "Unite" button appears under the "OK" button in the Custom Screen, and lights up whenever the player has previously selected a Battle Chip that is eligible for initiating the Soul. Initiating the Soul will sacrifice the Battle Chip and render it unusable for the rest of the battle, while also taking up a slot for selection for that turn (thus limiting the player to 4 chips for selection if he chooses to initiate a Soul at the same time). Souls last for 3 turns (including the one where they were initiated) by default, though Battle Network 5 introduced NaviCust programs that can prolong the Soul's duration.

Chaos Unison

Introduced in Mega Man Battle Network 5, Chaos Unison (カオスユニゾン, Kaosu Yunizon) occurs when sacrificing a Dark Chip. It is an immensely powerful transformation, having the attributes of both the power of the Dark Chip and Soul Unison. MegaMan gains the Soul's attributes, with an unusual Double Soul different color (usually turns purple or blackish). The charge attack now becomes the same as the sacrificed Dark Chip, and doing so does not affect Karma or have the effect of removing 1 HP permanently like using the chip normally would.

The catch is that Chaos Unison can only be used for absolutely one turn (cannot be boosted with the Navi Customizer), and when charging, the charge will rapidly transition between Teal-Green to Purple. If the player releases the Charge Shot while it is purple, the attack will execute flawlessly; if they release while it is teal-green, the attack fails and the Soul expires. Dark MegaMan is also spawned in the enemy area, and will proceed to harass the player with Buster shots and random chip attacks for 13 seconds or until the battle ends. For each consecutive time a Chaos Unison's Charge Shot is used successfully during the battle, its charge time will increase slightly, in an attempt to throw off the player's timing and raise the risk of failing it.

At the end of Mega Man Battle Network 5, the destruction of the Dark Chip factory following Nebula Grey's defeat renders Chaos Unison impossible, due to there being no Dark Chips to sacrifice anymore.

List of Double Souls

Below is the list of all Double Souls appearing in the games and anime.

Mega Man Battle Network 4
Red Sun Souls
Fire Soul/Torch Soul
	Requires a Fire chip sacrifice. Fire element, weak to Aqua. Some panels will be changed to Grass Panels once the Soul is initiated. MegaMan can absorb a Lava Panel and recover 50 HP by standing on it. Charging a Fire chip will unleash a Fire Arm that covers the entire row, doing Fire damage equal to the chip's power + 50. Charge Shot: Fire Arm Hits the 3 panels in front of MegaMan for 50 Fire damage.
Guts Soul
	Requires a Cracking chip sacrifice. Non-element Non-dimming, non-elemental chips gain 30 attack. Rapid tapping of the B button causes MegaMan to fire a Guts Machine Gun, hitting 6 times for 5 damage each. MegaMan is invincible during this attack's duration. Charge Shot: GutsPunch Hits the panel in front of MegaMan for 60 damage. If it hits an obstacle, the obstacle will be pushed backwards.
Roll Soul
	Requires a Healing chip sacrifice. Non-element Using any battle chip will restore 10% of MegaMan's max HP. Charge Shot: Roll Arrow Travels down the row, hitting for 30 damage. If the arrow hits an enemy with battle chips loaded, Roll Arrow destroys these chips.
Wind Soul/WindBlast Soul
	Requires a Wind chip sacrifice. Non-element All non-dimming Wind chips gain 10 attack. North Wind is performed when the Soul is initiated, removing all Barriers and Auras from all enemies. MegaMan's normal buster becomes a 5-damage Air Shot, which can shift positions of enemies and knock obstacles around. Float Shoes and Air Shoes are enabled. While the Soul is active, a Fan effect is present which pulls all enemies to the front row. Charge Shot: Wind Racket Hits a 1x3 area directly in front of MegaMan for 50 damage. Any enemies or obstacles it hits are knocked to the back row.
Thunder Soul
	Requires an Elec chip sacrifice. Elec element, weak to Wood. All non-dimming Elec and non-elemental chips will paralyze. Charge Shot: Zap Ring Fires down the row, hitting for 20 paralyzing Elec damage. The Charge Shot has a very slow charge rate such that paralysis expires before charging finishes.
Search Soul
	Requires a Stealth chip sacrifice. Non-element Invisibility will be removed from all enemies once the Soul is initiated. Search Shuffle is available in the Custom Screen, which randomly shuffles all chips in the Custom Screen that are not selected yet. This can be performed up to three times each turn while the Soul is active. Charge Shot: Scope Gun Locks onto the nearest enemy, doing five shots of 10 damage each. This attack pierces Invisible.
Blue Moon Souls
Aqua Soul/Spout Soul
	Requires an Aqua chip sacrifice. Aqua element, weak to Elec. MegaMan will not slip on Ice Panels. Non-dimming Aqua chips can be charged for double damage. Charge Shot: Bubble Shot Fires down the row, hitting the enemy and the panel behind it for 20 Aqua damage. The Charge Shot has an incredibly fast charge rate.
Number Soul
	Requires a Plus chip sacrifice. Non-element All non-elemental chips gain 10 attack. Custom Screen capacity is expanded to ten while the Soul is active. Charge Shot: Dice Bomb Throws a Dice Bomb three panels forward. If it does not hit the enemy, it will explode after a short delay, inflicting (10 x die roll result) damage to a 3x3 area around it. If it lands on an enemy, it only deals 10 damage.
Metal Soul/HeavyMetal Soul
	Requires a Breaking chip sacrifice. Non-element Buster shots can damage guarded enemies. Non-dimming Breaking and non-elemental chips can be charged for double damage. Charged non-elemental chips will also damage guarded enemies. Charge Shot: Metal Break Hits the panel directly in front of MegaMan, inflicting 150 Breaking damage and pushing the enemy back one panel.
Wood Soul
	Requires a Wood chip sacrifice. Wood element, weak to Fire. Status Guard enabled. MegaMan heals at an incredibly fast rate while standing on Grass Panels. Non-dimming Wood chips can absorb the next non-element Standard chips selected after them, adding the chip's displayed power to their own. Charge Shot: Wood Twister Hits two panels away for eight hits of 20 Wood damage each.
Junk Soul/JunkData Soul
	Requires an Obstacle chip sacrifice. Non-element All enemies are confused once the Soul is initiated. Two randomly selected used battle chips are recycled and placed in the two additional custom slots in the Custom Screen while the Soul is active. Chips recycled this way will not be replaced after use. Charge Shot: Poltergeist Dims the screen while throwing all obstacles at all enemies, inflicting 100 damage per obstacle.
Proto Soul
	Requires a Sword chip sacrifice. Non-element Reflect enabled. Navicust programs that require B + ← to execute will be overridden by Reflect. Non-dimming Sword chips can be charged for double damage. When MegaMan uses chips charged this way, he also jumps two panels forward before using the chip. Charge Shot: Wide Sword Hits a 1x3 area immediately in front of MegaMan for 80 damage.

Mega Man Battle Network 5
Team Colonel Souls
Knight Soul
	Requires a Breaking chip sacrifice. Non-element Non-dimming Breaking chips can be charged for double damage. MegaMan turns invincible when using any battle chip on his front row. This lasts until he is able to move again. Charge Shot: Royal Wrecking Ball Hits the eight panels surrounding MegaMan, inflicting (10 x Buster rank + 30) Breaking damage, while also confusing all enemies it hits. Chaos Soul Charge Shot: Dark Drill Hits the two panels ahead of MegaMan up to five times for 100 Breaking damage each. Enemies which are hit are pushed back, but if they cannot move any further from the drill they continue taking hits.
Shadow Soul
	Requires a Stealth chip sacrifice. Non-element Anti-Damage and Float Shoes enabled. Navicust programs that require B + ← to execute will be overridden by Anti-Damage. Charging a non-dimming Sword chip will cause MegaMan to execute said attack on the nearest enemy from behind. Movement speed slightly increased, with reduced waiting time between moving from panel to panel. Charge Shot: Long Sword Hits the two panels directly in front of MegaMan, inflicting (5 x Buster rank + 65) damage. Chaos Soul Charge Shot: Dark Invisible MegaMan turns black and becomes invincible and uncontrollable, moving about and attacking randomly with Buster shots, any loaded chips and any other Battle chips and Program Advances the player has used.
Tomahawk Soul
	Requires a Wood chip sacrifice. Wood element, weak to Fire. Status Guard enabled. Entire stage is converted to Grass Panels when Soul is initiated. MegaMan heals while standing on a Grass Panel. Using a non-dimming Wood chip while on a Grass Panel will double the chip's power, but the Grass Panel dissipates afterwards. Charge Shot: Tomahawk Swing Covers a 2x3 area immediately in front of MegaMan, inflicting (10 x Buster rank + 70) Wood damage. Chaos Soul Charge Shot: Dark Lance Hits the enemy back row for 400 Wood damage, pushing all enemies forward.
Number Soul
	Requires a Plus chip sacrifice. Non-element All non-elemental chips gain 10 attack. Custom Screen capacity is expanded to ten while the Soul is active. Charge Shot: Dice Bomb Throws a Dice Bomb three panels forward. If it does not hit the enemy, it will explode after a short delay, inflicting ((Buster rank x 5 + 5) x die roll result) damage to a 3x3 area around it. If it lands on an enemy, it deals damage only to that enemy as if the roll result was a one. Chaos Soul Charge Shot: Dark Plus Adds 50 attack to the next selected chip or Program Advance. This cannot stack with other modifiers used, except for Number Soul's innate +10.
Toad Soul
	Requires an Aqua chip sacrifice. Aqua element, weak to Elec. MegaMan is able to hide in Sea Panels, and cannot slip on Ice Panels. Non-dimming Aqua chips can be charged for double damage. All Aqua chips gain 30 attack while MegaMan stands on a Sea Panel. Charge Shot: Homing Note. Homes in on the nearest enemy, inflicting (10 x Buster rank + 20) paralyzing Elec damage. Chaos Soul Charge Shot: Dark Wide Shot Fires a Wide Shot that hits everything down the rows it covers for 300 Aqua damage.
Colonel Soul
	Requires an Obstacle chip sacrifice. Non-element Charge Shot can be converted to any non-dimming, non-element Standard chip while the Soul is active. Obstacles on the field convert to soldiers which attack enemies standing behind or to the side of them. Charge Shot: Screen Divide Covers a V-shape formation centred on the nearest enemy in the row, dealing (10 x Buster rank + 40) damage. If no enemy is present in the same row as MegaMan, the attack is instead centred 3 squares ahead. Chaos Soul Charge Shot: Dark Sound Summons a Trumpy virus that paralyzes all enemies while it plays its music.
Team ProtoMan Souls
Magnet Soul
	Requires an Elec chip sacrifice. Elec element, weak to Wood. Non-dimming Elec chips can be charged for double damage. MegaMan is unaffected by Magnet panels. B + ← will temporarily freeze all enemies in the same row as MegaMan. Charge Shot: Magnet Bolt Drags the nearest enemy in the row to the front of the area. If they are pulled to the panel in front of MegaMan, the attack deals (10 x Buster rank + 30) paralyzing Elec damage. Chaos Soul Charge Shot: Dark Thunder Creates a purple lightning ball that slowly travels and homes in on the nearest enemy, inflicting 200 paralyzing Elec damage.
Gyro Soul
	Requires a Wind chip sacrifice. Non-element Air Shoes and Float Shoes enabled. Using a non-dimming Wind chip will make MegaMan's propeller spin, doubling the damage dealt by the next non-dimming Wind or non-elemental chip used. The propeller will not stop spinning until the Soul expires, the battle ends, or a non-dimming non-elemental chip is used. Charge Shot: Tornado Arm Covers three panels in front of MegaMan, hitting once for the panel directly in front, twice for the panel after that, and thrice for the third. Each hit does (5 x Buster rank + 15) damage. Chaos Soul Charge Shot: Dark Tornado Hits the second panel in front of MegaMan eight times for 50 damage each. If MegaMan flinches, other tornadoes will appear around the original one.
Napalm Soul
	Requires a Fire chip sacrifice. Fire element, weak to Aqua. MegaMan takes no damage from Lava panels, but suffers a HP drain while standing on Sea Panels. Non-dimming Fire chips gain 40 attack. Standing on a Lava Panel with a damaging chip or Program Advance selected will remove the Lava Panel and give the chip an additional 10 attack. Charging a Fire chip will unleash a Napalm Bomb at the nearest enemy that deals Fire damage equal to twice the charged chip's power. Charge Shot: Fire Vulcan Hits down the row and behind the enemy it hits three times for (5 x Buster rank + 5) damage. Chaos Soul Charge Shot: Dark Meteor Summons a number of meteors that are targeted at enemies which hit for 100 Fire damage. These meteors will also crack and destroy the panels they hit.
Search Soul
	Requires a Cursor chip sacrifice. Non-element Invisibility will be removed from all enemies once the Soul is initiated. Search Shuffle is available in the Custom Screen, which randomly shuffles all chips in the Custom Screen that are not selected yet. This can be performed up to three times each turn while the Soul is active. Charge Shot: Scope Gun Locks onto the nearest enemy, doing five shots of (2 x Buster rank + 10) damage each. This attack pierces Invisible. Chaos Soul Charge Shot: Dark Circle Freezes time, and causes a cursor to quickly circle the enemy area perimeter. Pressing A will stop the cursor and hit the selected panel the next six panels for 300 damage each. Reducing the enemy area will cause this attack to hit multiple times.
Meddy Soul
	Requires a Recovery chip sacrifice. Non-element The last two custom slots are replaced by capsules that can be fused with selected chips to give additional effects: Pink: Recovers HP Black: Blinds White: Paralyzes Yellow: Confuses Purple: Causes a HP bug (Netbattle only) Charge Shot: Capsule Bomb Throws a capsule three squares ahead. If it lands on an unoccupied panel, there is a short delay before it explodes and hits the panels above and below it for (10 x Buster rank + 30) damage. Otherwise it damages only the enemy it lands on. Chaos Soul Charge Shot: Dark Recovery Recovers 1000 HP to MegaMan.
Proto Soul
	Requires a Sword chip sacrifice Non-element Reflect enabled. Navicust programs that require B + ← to execute will be overridden by Reflect. Non-dimming Sword chips can be charged for double damage. When MegaMan uses chips charged this way, he also jumps two panels forward before using the chip. Charge Shot: Wide Sword Hits a 1x3 area immediately in front of MegaMan for (10 x Buster rank + 70) damage. Chaos Soul Charge Shot: Dark Sword Hits a 2x3 area immediately in front of MegaMan for 400 damage.

Other Appearances

Megaman using Proto Soul.

In MegaMan NT Warrior Axess, MegaMan is able to perform Double Soul initially through a special bond between fellow Navis; he usually obtained new souls in dire situations, during which either he or the other Navi in question were subject to great peril. After initiating a given Double Soul once, Lan received a corresponding chip, allowing MegaMan to freely access it when needed.

While it is Double Soul that overrides MegaMan's Style Change option in the games, it is a side effect of Cross Fusion that serves this purpose in the anime.

All twelve Souls from Mega Man Battle Network 4 appear in Axess. Only one Soul from Mega Man Battle Network 5 (Gyro Soul) appears in the Stream season.

Manga

In the NT Warrior manga, MegaMan acquired the Double Soul program from Serenade and first used it during his third battle with Bass. Like in the anime, MegaMan is able to perform Double Soul through a special bond between fellow Navis. Unlike in the anime though, Lan doesn't receive a corresponding chip, requiring MegaMan's fellow Navis to be there for MegaMan to use Double Soul. Also, the Navis who perform Double Soul with MegaMan gives 99% of their data to MegaMan, leaving them at a state of near deletion. If the Navi who performs Double Soul with MegaMan is deleted, the respective Double Soul will disappear as well.

The secret Bass Soul and Laser Soul also appeared, but were used by Dark MegaMan.EXE instead of MegaMan.

Trivia

• Mega Man Battle Network 4 contains unused data of a Forte Soul (that name is also in the English version) and Duo Soul, but they can not be accessed with hacking due to the low amount of data left.
• The time period that Dark MegaMan appears following the fail of Chaos Unison charge shot is 13 seconds, a rather unusual nod to an unlucky number.

See also

• Style Change
• Cross System