From Sonic Retro
The Black Arms are an evil alien race lead by Black Doom in the 2005 game Shadow the Hedgehog. Their ultimate goal is to convert human beings into convenient sources of energy. To accomplish this end, the Black Arms require the seven Chaos Emeralds to allow the Black Comet to pass through Earth's atmosphere via Chaos Control. The Black Comet will then expel a paralysis-inducing nerve gas worldwide, eliminating any further resistance.
To secure the Chaos Emeralds and weaken the opposing G.U.N. army and Eggman's forces, the Black Arms plans are remarkably multifaceted. They deploy offensive forces to attack Earth's defenses directly, neutralize major cities, bases, and communications networks, collaborate with select humans (especially the late Dr. Gerald Robotnik), utilize weapons of mass destruction (such as the ARK's Eclipse Cannon), and even engage in quasi-religious propaganda. The pivotal piece in the success or failure of their designs, however, is whether they can convince Shadow the Hedgehog to assist their cause.
The Black Arms appear to have green blood, although they originally had red blood before it was edited due to censorship reasons.
Black Arm Species
The larvae are Black Doom's offspring, and seeing as how there are no (recognizable) female Black Arms, it is assumed that they reproduce asexually. They are blobs of flesh with spikes surrounding their one and only eye. Their small size makes them hard to see at hypersonic speeds and they can attach themselves to walls. Despite these slight advantages, any single attack will kill them
Bipedal beings who are just slightly larger and hardier than your typical human, these are the most common of the Black Arms. They tend to carry weaponry ranging from swords to guns, but occasionally appear unarmed, in which case they lunge and claw at Shadow. The Black Warriors often guard cages and must be killed to move on. Require two Homing Attacks to vanquish.
Small bat-like creatures who attempt to dive into Shadow. Any single attack will kill them. Serve mainly as the Black Arms's mandatory Homing Attack stepping stone.
Highly maneuverable bird-like creatures that fly about with ease. Certain members of their ilk fire blue energy waves in Shadow's direction. Others must be grounded, mounted, and flown through a bit of level in order to progress. Your steed will kick you off at a certain point, or you can do so prematurely by jumping.
Stronger forms of the Black Hawk with golden armor, all of which Shadow can ride. While flying through the skies, press an action button to fire off blue energy waves to clear the way of obstacles.
Giant Black Arms which carry swords, hammers and explosives launchers. They have have high HP and some can even negate damage from projectiles by blocking them with their hands.
These worm creatures like to burst from the ground. They also lob smaller homing worms at Shadow, due to the fact that they've swallowed weapons called "Worm Shooters". Deplete its health and the big worm bursts in a pulpy explosion, allowing Shadow to acquire the weapon formerly in its gut.
Stronger annelids that drop Golden Worm Shooters. The Golden Worm Shooters have more worms inside them.
These are heavily armored Black Warriors that carry powerful lasers called Refractors. They are commonly seen on Air Saucers and can teleport (possibly Chaos Control).
Flowers similar to Piranha Plants from Super Mario Bros, they spit up fire when approached. After so many attacks from the player, they retreat into a bud for about ten seconds before blooming once again into fiery destruction. They can't be destroyed permanently.
Crimson, stationary, spiky plant-like objects that serve to punish hedgehogs who zip around recklessly. Red Fruits tend to be found wherever there are Black Arms afoot, and according to Black Doom are symbols of the Black Arms' victorious conquests. They are also apparently poisonous, which may be why Shadow takes damage whenever he runs into them. Fortunately, Red Fruits are very fragile; any attack will cause them to splatter.
A gigantic flying Black Arm, this colossus has bat-like wings, a single cyclopedian eye, and spews fire from its maw. Black Bull's blubbery body is impervious to damage, the only weak point being its eye. The boss appears twice in Shadow the Hedgehog; first in Lethal Highway (fought with Sonic) and then in Death Ruins (fought with Rouge).
In the boss battle following Lethal Highway, Black Bull can be defeated quickly by taking out the Black Wings and Black Warriors which accompany it until Shadow has charged up his Chaos Control meter. During boss battles, Chaos Control stops time and weapon ammunition does not deplete in timestop. So by deploying Chaos Control when Black Bull's eye is vulnerable and using a gun with a good rate of fire, Shadow can fire lethal damage at the boss over the course of a single chronometric intermission.
As it turns out, Shadow is at least partly a desendent of Black Doom himself. Here's the full story...
Project Shadow, headed by Dr. Gerald Robotnik, was not progressing smoothly. In the course of Gerald and his cologues' research, they had only managed to create one relatively simple and increasingly disobedient prototypal artificial lifeform. Furthermore, time was not on their side; Maria Robotnik, the original inspiration for Gerald's involvement in the immortality project, was still stricken with degenerative NIDS, and the military was growing more and more wary of the project's results. Gerald needed a breakthrough, and Black Doom was more than happy to provide it.
During one of the Black Comet's 50-year rendezvous with Earth, Black Doom contacted Gerald and struck a deal with the struggling scientist: Black Doom would donate some of his seemingly immortal blood to aid the manufacture of a new artificial lifeform, and Gerald would lend the fruits of his labor to Black Doom fifty years in the future to assist with the Black Arms's search for the Chaos Emeralds. Black Doom's contributions were critical to Project Shadow's success; Both Black Doom and Gearld were present when Shadow the Hedgehog was successfully synthesized in Gerald's lab. Also witness to the event was the young boy who would grow up to be the G.U.N. Commander. He would associate the subsequent G.U.N. raid on the ARK resulting in the death of his family and friends with Black Doom and especially Shadow, carrying a pronounced hatred for the alien/hedgehog hybrid into his latter years.
Realizing that the bargain made with Black Doom was a mistake, Gerald Robotnik planned to use the Eclipse Cannon and Shadow's Chaos Control ability to shatter the Black Comet when the Black Arms returned to wreck havok on Earth fifty years later. Unfortunately, G.U.N. conducted their infamous raid aboard the ARK shortly afterward, killing numerous researchers and Maria Robotnik, imprisoning Gearld and Shadow at Prison Island, and sealing Project Shadow's prototype deep within the ARK. Distraught by the death of his granddaughter, Gearld went insane and repurposed Shadow and the Eclipse Cannon into the instruments of humanity's demise, leading to the events of Sonic Adventure 2.
Because Shadow shares physiology with Black Doom, he possesses many of the abilities of the alien leader. Both are seemingly immortal and can utilize Chaos Control (it is not seen if Black Doom can utilize similar techniques, such as Chaos Spear, or if Shadow can utilize all of the techniques Black Doom displays in battle). While Shadow's Black Arms blood apparently renders him immune to the paralysis gas emitted from the Black Comet, it is said to render him under the control of Black Doom if necessary, though after being shown an inspirational film of Gerald and Maria Robotnik revealing his true purpose, Shadow breaks free from Black Doom's direct manipulation.
Because the Black Comet was destroyed by Shadow and the Eclipse Cannon at the conclusion of Shadow the Hedgehog, and because it is unknown if any Black Arms survive on Earth or anywhere else, it may be assumed that Shadow the Hedgehog remains the sole descendent of the Black Arms.
- See main article: Black Comet
The Black Comet is the home of the Black Arms, and passes by Planet Earth every fifty years. Fifty years after Shadow's birth, it returns, starting the war between GUN, Dr. Eggman and the Black Arms. It is investigated three times in the game. In the Action Stage Black Comet, Shadow travels through the Comet and must either destroy the GUN troops or proceed to the worldlet's interior. In Final Haunt, Sonic and Shadow race across the surface and must find Black Doom. Alternatively, Shadow can flip some switches, which protects the Black Comet from any and all outsiders. And in the level The Last Way, Shadow races against the clock through the depths of the Black Comet. Eventually, it is completely destroyed by the Eclipse Cannon, wiping out the Black Arm race.