Phaaze is a planet featured in Metroid Prime 3: Corruption, it is the final location in the game, and the final location in the Metroid Prime trilogy. It is the source of all the Phazon in the universe.
Phaaze is a living planet. Deep within the planet's depths is a serpentine womb where Leviathans are born. The Leviathans, once they fully mature, leave Phaaze every 100 years, at which time, it sends them toward other planets to spread Phazon. They are capable of creating wormholes to get to their destination faster. After impacting a planet, the Leviathan dies, before which, it attracts a local powerful creature and mutates it to protect its core. Over time, the impacted planet becomes a clone of Phaaze.
A Chozo searcher on Elysia discovers Phaaze via a missing probe. However, the probe's data only provides minor details about the planet, showing the planet is somehow alive. The data is lost before the Chozo can fully analyze it, and additional research on Phaaze is made difficult, due to the planet being extremely far away.
The Phazon Crisis
Many years later, Dark Samus and the Space Pirates discover the planet. Dark Samus sends the Space Pirates to acquire an Aurora Unit so she can control the planet; the pirates attack the GFS Valhalla, stealing Aurora Unit 313 from the vessel, and Dark Samus implants the AU into Phaaze. With that done, she has the ability to send Leviathans at any planet she pleases. The first planet she sends a Leviathan to is the Space Pirate Homeworld. Dark Samus and the Space Pirates then proceed to send Leviathans at three planets important to the Galactic Federation: Norion, Bryyo, and Elysia, with an armada protecting each of them, and Dark Samus herself in charge of the attack on Norion. The strikes on Bryyo and Elysia succeed, but Samus and three other bounty hunters, Rundas, Ghor, and Gandrayda, manage to stop the Leviathan aimed at Norion from corrupting the planet, but not before Dark Samus corrupts them with Phazon.
Samus is unconscious for a whole month, and during that time, her comrades are sent to Bryyo, Elysia, and the Pirate Homeworld to tackle the Leviathans. Unfortunately, each of them succumb to the Phazon in their bodies. Thus, the Galactic Federation sends Samus to pick up their trails and finish the job.
After dealing with Phazon-corrupted monstrosities, as well as her corrupted allies-turned-enemies, and destroying the Leviathans on all three planets, the Galactic Federation discovers Phaaze. Taking control of a Leviathan battleship, Samus and Admiral Dane's Fleet head for Phaaze via a wormhole. While the fleet engages a Space Pirate fleet in orbit above Phaaze, Samus heads directly for the planet to deal with Dark Samus.
Setting foot on Phaaze, Samus's Phazon corruption goes to critical levels due to the Phazon in the planet's atmosphere, forcing her to vent all her Energy Tanks to prevent total corruption for the time being, and putting her in Hypermode permanently. In addition, due to near total corruption, Samus's ship denies her access as it no longer recogonizes her. To make matters worse, constant exposure to Phaaze's atmosphere and taking damage will cause Samus's Phazon level, represented by a yellow bar, to go up, killing her if it fills completely.
Traveling through the planet, Samus encounters various mutated creatures, all the while collecting Anti-Phazon Units to reduce her Phazon levels. Eventually, Samus reaches the core of the planet, where she comes face-to-face with Dark Samus. After a fierce battle, Samus manages to overpower Dark Samus, who summons Aurora Unit 313 and merges with it. With a little difficulty, Samus defeats the corrupted Aurora Unit 313 as well, and due to the AU's symbiotic connection to Phaaze, its death causes Dark Samus to perish for good, and also causes Phaaze to explode, finally putting an end to Phazon once and for all.
- The planet's name was first given in a Q&A on the Japanese Metroid Prime 2: Dark Echoes website. Metroid Prime: Federation Force mentions the planet in its introduction.
- An unusual constellation appears in the sky above Phaaze, which art director Todd Keller intentionally designed to resemble the outline of a Metroid.
- The presence of mutated strains of Metroid and their hives, along with husks seemingly belonging to a single or numerous Metroid Primes living on Phaaze suggest that Metroids are native to both SR388 and the Phazon planet. In addition, this also led to the theory of the final boss from the first Metroid Prime game having originated from Phaaze and reaching Tallon IV via a Leviathan.
- However, as a result of official media related to the Metroid series stating SR388 to be the single homeworld of the titular species, along with the Space Pirates' known habit of importing said species to different planets, it is more likely that the Metroids were introduced to Phaaze by the marauding race and their leader, Dark Samus. The massive population can be attributed to specific mutants capable of reproduction, such as Metroid Hatchers and other Metroid Primes. The most consistent theory explaining the origin of Tallon IV's Metroid Prime can be found here.
- The destruction of Phaaze due to the defeat of Aurora Unit 313 is very similar to the destruction of Zebes after Mother Brain is destroyed by Samus in Super Metroid.
- Aurora Unit 242 is the one to inform Samus that the Galactic Federation named this planet "Phaaze". However, certain Space Pirate Data entries that can be uncovered before the transmission 242 gives use the same name.
- AU 242 suggests the Pirate Homeworld may have also become a secondary Phaaze due to the mass corruption of Phazon and possibly transformed the said planet into another Phazon source as well.
- Phaaze is the second planet chronologically destroyed in the Metroid series, preceded by Dark Aether, then followed by Zebes and SR388.
- When Samus first enters Phaaze, a cutscene is played of her ship entering the atmosphere. This is only one of two instances in which the cutscene is seen, the other being the arrival on Norion.
- There is a possible mention of Phaaze in the Chozo Lore "Great Poison", where the Chozo theorize one planet once was coated with the Great Poison, and meteors from it spreading the Great Poison to the far corners of the universe.