Perfect Dark Gaia

Perfect Gaia is the final form of Dark Gaia from Sonic Unleashed

Origin
Perfect Gaia was created after the negative energy from The Werehog was drained and absorbed by Dark Gaia.After Sonic took out Dark Gaias 3 eyes,he change dinto Perfect Gaia.Sonic then used the Chaos Emeralds to transform into Super Sonic to defeat Dark Gaia once end for all.

The Grand Finale
After being defeated by Super Sonic,Perfect Gaia reverted back to Dark Gaia and was sealed within the Earth again.Dark Gaia was never heard from again.

Links
The battle against Perfect Gaia(Wii/PS2 version)

The battle against Perfect Gaia(PS3/360 version)