Dark Samus

Dark Samus is Metroid Prime taking on the form of Samus Aran.

Biography
After Samus defeated Metroid Prime on Tallon IV, it took her Phazon Suit and exploded. As Samus left the planet, inside the crater where they fought, in a pool of Phazon, an arm appeared out of it with an eye on the hand. This was Metroid Prime, reborn as Dark Samus. When Metroid Prime had taken the Phazon Suit, Samus's DNA merged with Metroid Prime's DNA, letting the Prime grow itself new, more stable body using Samus' DNA and its own to make needed organs and skeletal support to fill the Phazon suit, as evidence by some of the unlockable images in Metroid Prime 2.

Dark Samus manages to leave Tallon IV, looking for more Phazon. She eventually discovered the planet Aether, a planet with two dimensions. A Leviathan from Phaaze had previously landed on the planet, causing the planet to have two dimenions and cause the spread of Phazon on the planet. Dark Samus explored Aether and absorbed any Phazon she could find on the planet. It is unconfirmed what native creature the Leviathan used to protect its core, but it is likely that the creature became the Emperor Ing. Due to the similarities between the Emperor Ing's first, natural form, the Inglet, and the Phaazian creature "Phaz-Ing" it can be safely determined (though unconfirmed) that the Ing race is descended from a "Phaz-Ing" chosen by the Leviathan that impacted Aether, further altered by it's presence in the Dark Realm. This is supported by the presense of the term 'Ing' in both names.

The Space Pirates also had a base on Aether. Once Dark Samus arrived on Aether, they first thought she was Samus Aran. Her dark suit and her forceful invasions to obtain Phazon confused them, and they began to refer to her as the Dark Hunter. Samus eventually landed on Aether (to the horror of the Space Pirates) to investigate what happened to a team of Galactic Federation marines who had landed on the planet in pursuit of a Space Pirate frigate that crashed on the planet. Samus first encountered Dark Samus in the Temple Grounds, where Samus follows her in a portal to Dark Aether. She finds Dark Samus absorbing Phazon, after Dark Samus absorbs the Phazon, Dark Samus fires a shot at an energy crystal keeping Samus alive from Dark Aether's toxic atmosphere, then Samus gets attacked by the dark world's native inhabitants, The Ing. She escapes trough the portal realizing some of her gear was stolen. The next encounter takes place in the Agon Wastes. There, she had her first battle with Dark Samus. Once Dark Samus was defeated, she collapsed and faded into a cloud of blue particles.

However, Dark Samus had survived her encounter with the true Samus. The particles that Dark Samus transformed into somehow managed to transport itself to Torvus Bog. Samus saw the cloud transform into Dark Samus, though did not fight Samus. Instead, she laughed and disappeared. Samus later saw the same cloud in the Sanctuary Fortress, and it once again transformed into Dark Samus. She then destroyed the bridge to Sanctuary Fortress and left, requiring Samus to find an alternative route.

Samus later saw Dark Samus firing at several Dark Pirate Troopers. She disposes of them and begins to absorb some Phazon. Samus eventually managed to reach Dark Samus and fought her in a tall elevator shaft. Samus once again defeated her, and did not encounter her again for a long time.

Once Samus had defeated the Emperor Ing, she had seven minutes to escape Dark Aether. However, Dark Samus suddenly appeared, forcing Samus to battle her. Due to the huge amount of Phazon Dark Samus had absorbed, she was now a being comprised mostly of Phazon energy, and her suit was transparent, revealing organs, also making out a head similar to Metroid Prime's second form from the end of Metroid Prime. The eye seen in the back of the left hand is the same seen on the hand that emerged from the Phazon pool at the end of Metroid Prime.

Samus and Dark Samus battle in two phases, though Samus defeats her once again. She tried one last attempt at defeating Samus by trying to absorb Samus's Light Suit, though disintegrates just before she touches her. Samus escapes Dark Aether and brings peace to the Luminoth on the planet.

However, somewhere in space, blue particles floated. They eventually coalesced into solid form--Dark Samus.

In Metroid Prime 3: Corruption, she now has an alliance with the Space Pirates and is creating Leviathans, corrupting various planets with Phazon. Samus and the other Hunters first meet Dark Samus on Norion in which she quickly dispatches all four of them and corrupts them with Phazon. She reappears throughout the rest of the game in wraith-like form until the final battle on Phaaze in which she and Samus fight to the death. Samus triumphs and Dark Samus explodes in a bright explosion of Phazon, taking Phaaze with her shortly afterwards.

Attributes
As Dark Samus, the creature utilized many abilities similar to Samus, in more powerful forms. It could fire Phazon beams at enemies, and use Phazon-charged Super Missiles to blast opponents into bits. She could also do a charge up attack that made a dive bomb to the the character, a Phazon Boost Ball that generated vast amounts of kinetic energy in alarmingly short times, and raise shields of pure Phazon energy in this form. However, when Dark Samus consumed too much Phazon, she gained the disadvantages she had in her previous form: Phazon fired at her could overload and destabilize her, resulting in her generating very powerful Phazon attacks to discharge the used Phazon radiation from her body, including a pure beam of concentrated Phazon.

The Metroid Prime is a very durable life-form, surviving a massive destabilization, and traveling unaided through space and freely between the Dark and Light Dimensions. It can survive in the vastness of space, travel through it, and live through the explosions of planets, even dimensions. This is how it has constantly been able to regenerate itself after defeat and fly to another planet for Phazon absorption. Metroid Prime 3: Corruption reveals Metroid Prime (or Dark Samus) to be sentient and capable of long-range planning, through a series of Space Pirate data logs that record the fanaticism she inspires among a group of Space Pirates whose minds she warps. They detail her plans and how she reacts to certain events, and credit her with being something near a deity whose rule of the galaxy will be great.