Aurora Unit 313 is an Aurora Unit that was stolen from the G.F.S. Valhalla and was implanted into the planet Phaaze by Dark Samus. It was battled by Samus Aran five months later and is the final battle of Metroid Prime 3: Corruption.
313 was one of the first Aurora Units that was created by the Galactic Federation. It was stationed in the G.F.S. Valhalla, as Aurora Unit 242 was stationed on the G.F.S. Olympus. It was aboard the Valhalla as its crew was in the middle of a Training Exercise, and was attacked by Space Pirate Boarding Vessels. 313 couldn't protect the ship and made a final log entry stating information about Phaaze.
313 was implanted on planet Phaaze by Dark Samus to spread Phazon corruption and Leviathans throughout the galaxy. After Samus arrived on the planet and encountered Dark Samus, The doppelganger entered the unit and used it to battle her. Samus destroyed 313 along with Dark Samus and stopped the flow of Phazon throughout the galaxy.
- "Aurora 313 has somehow been fused with the bioessence of Dark Samus. While combat shields protect most of the unit, a weak spot has been detected at the cable junction. Damaging the unit's core will expose this point, but the core itself is protected by an armored hatch. Tentacle ports can be damaged to initiate stunning cerebral-feedback pulses within the target. While incapacitated, the hatch will be unprotected and able to be pulled open. This unit has been heavily mutated by Phazon exposure. It appears to be symbiotically connected to the planet Phaaze as well." — Logbook "Aurora Unit 313" (Metroid Prime 3: Corruption)