Great Repliforce War

The Great Repliforce War (レプリフォース大戦) is a major conflict of the Maverick Wars, fought between the Repliforce and the Maverick Hunters. The two factions were originally allies until Sigma manipulated the events that put the two "at each other's throats": framed for the destruction of a city and labeled Mavericks, the proud Repliforce announced their independence and the Maverick Hunters were ordered to stop the coup.

The Great Repliforce War is marked for both its moral ambiguity and for being fought in a greater personal level compared to previous Maverick uprisings; pride turned friendships into bitter rivalries and former friends fought to the death. Feelings of guilt would plague survivors of the war, even leading to a change of management in the Maverick Hunters.

Beginning
Sigma makes his first attempt at inciting enmity by trying to convince the General of Repliforce that the Maverick Hunters are a threat, painting them as the humans' puppets. When his arguments are rejected by General, Sigma convinces the combative 14th Unit member Magma Dragoon to betray the Hunters for a chance to fight Mega Man X. Using the Mechaniloid Eregion, Dragoon incites chaos in the aerial city of Sky Lagoon, luring the Repliforce and making it seem responsible for the attack. Just as the Hunters arrive to investigate, Dragoon causes Sky Lagoon to crash, leading to innumerable casualties.

Although Zero finds Iris in the area and rescued her, and her brother Colonel arrives to save her. Colonel refuses to disarm and follow the Hunters to HQ under suspicion of Maverick behavior. This leads to the humans and the Maverick Hunter Command Center labeling the entire Repliforce as a Maverick army.

The Coup
Indignant at the accusations, General announces the independence of Repliforce, swearing to build a Reploid-only nation. The Repliforce launches their coup with full force, occupying several cities and carrying out a number of military operations:
 * Web Spider and Frost Walrus oversee the construction of secret weapons at the Jungle and the Snow Base.
 * Storm Owl commands the Air Force.
 * Jet Stingray destroys a city and escapes to the sea.
 * Slash Beast defends the Repliforce's supply route aboard their Military Train.

The Hunters are immediately scrambled to combat Repliforce, with X and Zero fighting in the front lines. The two Hunters take on each Repliforce unit and come to blows with Colonel, their pleas to stop the coup unheard. Even though Magma Dragoon is destroyed and the truth behind Sky Lagoon revealed, it is far too late to dissuade Repliforce.

Due in large part to X and Zero, most of the Repliforce units are destroyed, but the Repliforce ups the ante by assembling at the Space Port. Colonel dies in battle with the Hunters, giving Repliforce the time needed to migrate to their Final Weapon in space, where they hope to establish their own nation. X and Zero quickly invade the Final Weapon, but X's subordinates in the 17th Elite Unit are assassinated by Sigma's spy Double, who is destroyed by X while a distraught Iris perishes during a quarrel with Zero, prior to the eventual confrontation with the General himself.

It is during the fight with General that the Final Weapon is taken over by Sigma and set to fire at the Earth. Although Sigma is defeated, The Final Weapon can no longer be stopped. Finally realizing his foolishness, the General uses his own body to jam the weapon and cause its destruction, saving the Earth.

Aftermath
The war ends with a bittersweet victory for the Maverick Hunters and the Repliforce decimated. The Maverick Hunter commander retires out of guilt, being replaced by Signas. Months later, what remains of the Reploid Air Force is infected by the Sigma Virus during the Earth Crisis, along with their commander Spiral Pegasus.

Sightings of battleships with the Repliforce symbol were documented one century after the Elf Wars, in use by Neo Arcadia's Deep Sea Squadron.

Notes and Trivia

 * The term "Great Repliforce War" was coined by Mega Man X: Official Complete Works.
 * Keiji Inafune wanted some moral leeway in the story of Mega Man X4, with the Repliforce not coming across as an evil presence like Sigma does. The point was to show that good and evil are not always as clear as people would like them to be.