Gorea is an immensely powerful sentient lifeform of unknown origins. Its original form is a misty gas, which assimilated the appearance of an Alimbic, albeit with three legs instead of two. It has been trapped within the Seal Sphere aboard the Oubliette for a long while, but is unintentionally released by the Hunters in Metroid Prime: Hunters.
Gorea has many warlike abilities. It is capable of assimilating weapons used against it and using them itself. It is also able to drain the life-force of creatures and leave them an empty husk, in a very similar way to a Metroid. It may require to physically contact the life-form or weapon for both of these abilities. In a similar fashion to the life-energy draining capability, it can latch onto and drain the energy from non-organic objects, such as the Seal Sphere. It is very durable, resisting the varied attacks by the Alimbics, survived after being fought by Samus Aran, using every weapon in her arsenal to damage it, and could only be truly defeated through the use of the Omega Cannon, which in itself seems to be of a futuristic thermonuclear energy. It is capable of psychic talents such as telepathy, sending out a message from its prison aboard the Oubliette to all civilisations in every language. Finally, Gorea may also be able to change it's appearance, or at least whilst in its gaseous state.
In Alimbic Lore, it was stated to have fallen from the sky in a Leviathan and impacted Alinos, carving a large crater upon the planet's surface. Then it rose from the meteor's debris as a gas, before taking on the form of the Alimbics looking upon it, and screaming its name: Gorea. It then set out to destroy the Alimbic Cluster. Eventually, after the Alimbics had tried everything they could to destroy it, they created the Oubliette and used their own souls to bind Gorea to the Seal Sphere, trapping him within it, and imprisoning the sealed Gorea within the Oubliette. It was then sent into another dimension with the Alimbic Cannon, and the keys to reactivating the cannon and revealing the Oubliette, the Octoliths, were hidden upon the Alimbic planets, guarded heavily. Many years later, Gorea was able to telepathically send out the message of 'The secret to ultimate power lies within the Alimbic Cluster' to all the universe's civilisations, causing the arrival of several Bounty Hunters to try and claim the power. Samus Aran is able to collect all the Octoliths and fire the Alimbic Cannon, revealing the Oubliette. She and the other hunters flocked there to search for the 'ultimate power', and accidentally released Gorea, who stole their abilities and almost killed them. Samus arrived late and commenced battle with Gorea. She was not only able to defeat Gorea first form, but by using the Omega Cannon she found she was able to destroy his second form and wipe him out, avenging the Alimbics and saving the Hunters and the universe from Gorea's wrath.
It is possible that Gorea was not destroyed at the end of Metroid Prime: Hunters. The player's kill count, tallying the total of enemies destroyed, including bosses, in the game, does not increase when Gorea is slain, in either form. This could mean that it had survived. Interestingly, the player does not actually see Gorea being destroyed. It erupts into flames, though these seem to originate and burst out from the Seal Sphere. Also, Gorea's body is more-or-less whole when the body is barely seeable due to the flames bar the eye, which is still somewhat visible when it cuts to Samus beginning to escape the Oubliette. It is therefore possible that the Seal Sphere was the thing being destroyed and not Gorea itself, who might have escaped if it could detach itself from the Seal Sphere. This perhaps could have been done if Gorea had regressed back into his original gaseous state, before proceeding to escape the Oubliette. With Dark Samus, when she was defeated and then existed as Phazon particles in the air on Dark Aether, she was able to survive the dimensions destruction by being in such a gaseous state. This may be true for Gorea also, who as a gas, if it had not already escaped the Oubliette, would not have been destroyed in its explosion.
Gorea has appeared only once in the series so far:
 Metroid Prime: Hunters
In Hunters, before the events of the game it lured several Bounty Hunters to try and release it under the false assumption of an 'ulimate power'. It fought with Samus Aran in two different forms after it was released and drained the Hunters.
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