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Dr. Cain

From Mega Man Wiki
Character Info
MMX2 - Dr. Cain Art.png
Artwork from Mega Man X2.
General information
Name(s):Dr. Cain
Appearances:Mega Man X (mention), Mega Man X2, Mega Man X3, Mega Man X4 (mention), Mega Man Xtreme, Mega Man Maverick Hunter X
Voice Info
Voice (JP):Tadashi Miyazawa
Voice (EN):Mike Shepherd

Dr. Cain (Dr. ケイン) is a supporting character in the X era, particularly the series' early installments. He is a robotics scientist and archaeologist who discovered X in 21XX after he was sealed away by Dr. Light. With this information, Dr. Cain helped put Reploids into production and usher in a new era of robotics.

In the Games

Mega Man X

Concept art from Mega Man X.

Dr. Cain is first mentioned in Mega Man X, though he does not appear in-person in the game. His most prominent reference is in "The Journal of Dr. Cain", a portion of the game manual written as journal entries from Cain's perspective to tell the story of X's discovery and the production of Reploids. The journal begins on April 8th, describing Cain's lack of success in an archaeological dig to verify his findings on Mesozoic plant life.[note 1] On April 10th he excavated Dr. Light's laboratory, and on April 14th he awoke X from his capsule. On November 22nd, Cain and X successful created the first Reploid based on his design, and Reploids soon went into mass production. After Reploids eventually began going Maverick, Cain founded the Maverick Hunters and created Sigma, his Reploid magnum opus, to command them. However, inevitably Sigma too would go Maverick on June 4th, forcing X and Zero to stop him.[1][note 2]

The game's opening shows Dr. Cain logging into a computer to access records of Dr. Light's data on X, displaying "Mega Man X Specifications" and "Warning" messages.

Mega Man X2

Sprite from Mega Man X2.

Dr. Cain first appears in-person in Mega Man X2, where he takes a more involved role leading the Maverick Hunters and supporting X. After Zero's sacrifice during Sigma's rebellion, Dr. Cain salvaged his control chip, but was unable to reconstruct his unique Reploid body.[2] Six months later, when Mavericks were found with microchips bearing Sigma's insignia, Cain traced their source to a secret factory making Maverick soldiers for a new rebellion.[3]

When X is challenged by the X-Hunters in Hunter Base, Dr. Cain urges him to defeat them and recover Zero's parts so he can be reconstructed. Once all eight Mavericks are defeated, he pinpoints the location of the X-Hunters' Arctic base so X can finish the fight. If X failed to defeat all three X-Hunters, they storm Hunter Base and steal Zero's control chip from Cain, as he is helpless to stop them, leading to Zero being resurrected as a Maverick. If X successfully defeated all three, Cain reassembles Zero off-screen in time for Zero to help X fight Sigma in the game's finale.

Mega Man X3

Dr. Cain returns in Mega Man X3, staying at Hunter Base as usual while X and Zero fight against Dr. Doppler's rebellion in Dopple Town. Once all eight Mavericks are defeated, Dr. Cain analyzes their remains to pinpoint Doppler's laboratory hidden at Point D. He also discovers that Doppler is constructing a giant battle body, though he appears to be incompatible with it, leading X and Zero to suspect it is for Sigma instead. If Zero is damaged by Mosquitus in Doppler Stage B, he is forced to get repairs from Dr. Cain while X finishes the fight.

Additionally, in the English version's game manual, "Cain Labs" is credited for creating a Reploid-focused website called "Reploids on the Web" that serves as a framing for the manual's information.

Mega Man Xtreme

Sprite from Mega Man Xtreme.

Dr. Cain has a minor role in Mega Man Xtreme, working with Middy at Hunter Base to find a way to restore the Mother Computer, while X fights the Maverick data guardians within. He only appears in-person once X defeats all four Mavericks to congratulate him on clearing the obstacles, and again once X completes Sigma Stage 2 to inform him that he can finally enter the core.

Mega Man X4

Dr. Cain is only briefly mentioned in Mega Man X4, making no in-person appearance. The first reference is in the English version's game manual, which mentions Cain was involved in the formation of Repliforce. It also claims that Cain created Double, though this information has never been referenced in any subsequent material, leaving its canon status debatable. The other reference is in Zero's flashback cutscene, where Sigma orders his men to retrieve the defeated Zero for study by Dr. Cain.

Mega Man Maverick Hunter X

Concept art from Mega Man Maverick Hunter X.

In the remake Mega Man Maverick Hunter X, Dr. Cain appears in the animation "The Day of Σ" and is arguably the character most different from his original appearance. While he remains the discoverer of X and creator of Sigma and the Reploids, he is now bound to life-support technology in his home in Abel City. Sigma reports to Dr. Cain on the Maverick Hunters, and Cain surprises him by emphasizing that X is still the most advanced Reploid for his profound emotional complexity. This gets Sigma to consider X as a benchmark for Reploid evolution, and to involve him more in his plan to surpass humanity. When Sigma begins his rebellion, he launches a missile strike on Abel City that apparently kills Cain, as he is shown ironically refuting that Reploids are punishment for mankind's hubris before being consumed in light.

Other Game Appearances

Other Media

  • In the Mega Man cartoon, Dr. Cain is briefly shown on a monitor in the episode "Mega X". As Mega Man X2 had not established an official design for him yet, Cain was depicted as a younger man with brown hair and a beard.
  • In the Rockman X manga, Dr. Cain plays a much larger role than in the original game. He also returns as a major character in the Rockman X2 and Rockman X3 manga.
  • In Rockman X The Novel: Irregulars Report, Dr. Cain is featured as a major character.
  • In the Archie Mega Man comic, Dr. Cain appears during the Mega Man X issues, including a portion directly based on "The Journal of Dr. Cain" and its events.

Official Data

Source Data
Mega Man X Legacy Collection Gallery (X2) The most gifted roboticist of the 22nd century. Dr. Cain's groundbreaking development of Reploids broke down the barriers between robot and human as his creations exhibited the capacity to think, feel, and make decisions for themselves. Dr. Cain now spends his days as the founder and director of the Maverick Hunters, but he remains a mysterious figure even to those closest to him.
Mega Man X Legacy Collection Gallery (X3) The most gifted roboticist of the 22nd century. Dr. Cain's groundbreaking development of Reploids broke down the barriers between robot and human as his creations exhibited the capacity to think, feel, and make decisions for themselves. Dr. Cain now spends his days as the founder and director of the Maverick Hunters, but he still bears guilt for the damage caused by his creation, Sigma. He understands X's problems and often supports him from behind the scenes.


  1. In the Japanese version of "The Journal of Dr. Cain" (from the Windows version manual and Compendium of Rockman X), Dr. Cain's findings were on Middle Ages plant life instead.
  2. The dates after November 22nd differ in the Japanese version of "The Journal of Dr. Cain", being on average a month or two later than the dates in the English version. Additionally, Sigma led the Hunters for two years with no issues rather than four months.


  1. "The Journal of Dr. Cain", Mega Man X. 1993.
  2. Gallery, Mega Man X Legacy Collection. 2018.
  3. Opening, Mega Man X2. 1994.

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