Zero Space

Zero Space (零空間) is the final stage in Mega Man X5. It is a Cyberspace area that materialized in southeast of Asia, specifically at Point 11F5646, due to the influence of the Zero Virus. The Zero Space consists of four stages, each of which X and Zero must go through to investigate. It becomes accessible if the Enigma succeeds, after the Space Shuttle is used, or the countdown in the stage select screen runs out.

The player will return to the stage select screen after each stage is cleared. If Eurasia is destroyed, the player may switch characters normally between each stage. However, if Eurasia crashes, X will be the only character available.

Characteristics
Zero Space is a spatial anomaly created after the space colony Eurasia either crashes or is destroyed. The affected area turns into a facsimile of Cyber Space, resulting in a digitized atmosphere. The structures in Zero Space are composed of flat surfaces with transparent foundations patterned after circuitry. Massive amounts of data flow continuously in the background, which changes color between the first three stages (from blue to purple, then red). The background reverts to blue in the final stage, but the pattern changes into a series of complex circles which rotate endlessly.

The Zero Virus thrives in this environment, and its power allows even programs to escape Cyber Space and make their presence here.

Canon
Although the Earth is saved (collateral damage notwithstanding), Zero is still bothered by his unusual reactions to the Sigma Virus, and, upon learning about the creation of the Zero Virus, he decides to investigate Zero Space for clues. Concerned about Zero's viral readings, X decides to stop him, but Zero refuses to return and a fight ensues. The two Hunters reach a stalemate, knocking each other out. Sigma attempts to use the opportunity to destroy the unconscious X, but Zero recovers in time to repel Sigma, who decides to retreat. Sigma is soon defeated, but his explosion leaves Zero severely damaged. When X arrives to help him, Sigma's head fires a laser through X's back, then Zero lands a final shot with the Zero Buster. Zero dies soon afterwards, but X's body is found and restored by an unidentified entity as Zero Space vanishes.

Non-canon (Eurasia crashes)
Following the fall of Eurasia, Zero is infected with such quantities of the virus that his true self begins to shine through, turning Zero into an evil robot bent on destroying X. Feeling the evil in Zero, X accepts the challenge and rushes to confront him deep in Zero Space. The two Hunters are knocked out and Sigma tries to use the opportunity to destroy X, but Zero shields him with his body, dying with the attack. Sigma retreats, but he is followed by an outraged X, who defeats him after a hard battle. Sigma's explosion leaves X critically injured, but he is restored by an unknown entity who also decides to erase "all the painful memories". X returns to the Hunters afterwards with no memory of Zero.

Zero Space Stages
The Zero Space comprises four stages. If Eurasia is destroyed, the player may switch characters normally between each stage. However, if Eurasia crashes, X will be the only character available.

Zero Space Stage 1: Origin
Zero Space Stage 1: Origin (零空間ステージ1 起源), the entrance, is basically a long descent with many hurdles. The Zero Virus will occasionally appear to infect X or Zero, while Eagle Gs will occasionally block the path. However, the most dangerous obstacle is a series of laser barriers that will activate as the player enters their range. Contact with the lasers means instant death. X/Zero need to dodge the lasers or use Dark Hold to pass the area safely.

Enemies:
 * Eagle G
 * Spike Marl
 * Zero Virus

Boss:
 * Shadow Devil

Zero Space Stage 2: Grief
Zero Space Stage 2: Grief (零空間ステージ2 哀愁) begins with a vertical area with spikes and enemies and ends in a horizontal area that needs to be climbed by using ropes and Wall Kicks while avoiding the enemies and spikes.

In the beginning, several Eagle Gs are stationed across a path that ends with a large abyss, where moving platforms lead to a long corridor above. The route is filled with Crusher NEOs and Walk Shooters prior to a series of spikes where more Eagle Gs await. The path leads to a wide shaft where climbing is hindered by spikes, shooters and yet more Eagle Gs. At the top lies the room where Rangda Bangda will be fought.

Enemies:
 * Crusher NEO
 * Eagle G
 * Hover Gunner
 * Sniper
 * Walk Shooter
 * Zero Virus

Boss:
 * Rangda Bangda

Zero Space Stage 3: Awakening
Zero Space Stage 3: Awakening (零空間ステージ3 覚醒) starts with a downwards path leading to a series of wires the player has to latch into in order to cross a series of spikes and pitfalls. The path after this point has no enemies, but it is almost entirely covered with spikes with a few moving platforms. There is a shaft after this point where a Light Capsule is hidden. If X appears without an armor, he will receive the Ultimate Armor, while Zero will receive an upgrade. It is possible to obtain both by dying in the stage and returning with the other character. The final section is another abyss with platforms being the only way through. The boss will be either X or Zero depending on which character the player is using.

Enemies:
 * Metall T
 * Hover Gunner
 * Seil Gabyoall

Boss:
 * Zero/Awakened Zero (as X)
 * X (as Zero)

Zero Space Stage 4: Birth
Zero Space Stage 4: Birth (零空間ステージ1 誕生) begins with a long fall followed by a horizontal path with very irregular terrain, where the ceiling is entirely covered with red spikes. The path eventually changes into a series of platforms guarded by Hotarions and Eagle Gs above a long spike bed, which leads to a room with eight teleportation hatches which lead to "rematches" against the eight Maverick bosses.

After all eight are defeated, a ninth hatch will appear in the middle, leading to an horizontal path filled with many Killer Spheres and TriScan Golds, followed by a vertical shaft with more TriScan Golds just before a large final pit where a sequence of Appearing Blocks creates a route to the room where Sigma awaits.

Enemies:
 * Dejira
 * Eagle G
 * Hotarion
 * Killer Sphere
 * Spark Gunner
 * Spike Marl
 * TriScan Gold

Bosses:
 * Rematches (from left to right): Burn Dinorex, Dark Necrobat, Shining Firefly, Volt Kraken, Tidal Whale, Crescent Grizzly, Spike Rosered, Spiral Pegasus
 * Sigma (1st form)
 * Sigma (2nd form)

Trivia

 * Another possible translation for "零空間" is "null space", which may be a direct reference to the concept of null space of linear algebra.
 * In the collected soundtrack, the two themes for Zero Space are labeled "ZERO STAGE 1" (used in the first three stages) and "ZERO STAGE 2" (used in the final stage).
 * The stages of Zero Space make several throwbacks to past games of the Mega Man and the Mega Man X series.
 * The lasers of Zero Space Stage 1, as well as most of the layout, are based off Quick Man's stage. The lasers can be stopped with the Dark Hold, similar to how the originals could be halted with the Time Stopper.
 * The boss from Zero Space Stage 1, Shadow Devil, and the music that plays during its battle is a throwback to the Yellow Devil from the first Mega Man game. Also, the Shadow Devil can take the shape of the Wily Machine 6.
 * Zero Space 2 has a striking resemblance to the first stage of Sigma's hideout in Mega Man X. The boss is a new version of Rangda Bangda, complete with a remix of the original fortress boss theme from Mega Man X.
 * The music in the final stage is a remix of Quick Man's theme, while the stage itself is also a homage tribute to both Bubble Man and Heat Man from Mega Man 2.
 * In Mega Man Zero 3, new rifts to Cyberspace are created by the resonance between Omega and the Dark Elf; however, the Cyberspace featured in this game does not have the digitized aspect of Zero Space.
 * Area N of Mega Man ZX shares with Zero Space the same strange phenomena, where data takes on material form. Both places are also the result from the impacts of artificial celestial bodies (Ragnarok and Eurasia respectively).