The Scream of Perfect Chaos
From Sonic Retro
As Sonic and Knuckles ponder the implications of this news, they experience a vision of the Knuckles Clan attacking the Master Emerald shrine, in spite of Tikal's protests. Chaos delivers a devastating counterattack, leaving Tikal the only survivor. Tikal approaches the Master Emerald and begs for the destruction to end, and the vision ends as she is enveloped in light from the Emerald.
Knuckles observes that fortunately, not all the Chaos Emeralds have been gathered yet...but at that moment, Chris arrives with the last one. Chaos surges out of the ground and consumes it, and then proceeds to flood Station Square in the form of Perfect Chaos.
Eggman launches Egg Carrier 2 to combat Chaos, but Chaos explodes the entire ship with a single laser breath. Sonic's attacks also prove ineffective. As Sonic regroups with Tails and Chris, Tikal's spirit materializes before them, and she explains how Chaos has extracted the Chaos Emeralds' power with anger and sadness. As Sonic's friends--and a temporarily humbled Eggman--bring the Emeralds to Sonic, they begin to glow again, and Sonic transforms into Super Sonic. Tikal, Knuckles, and Tails observe that Sonic's caring for his friends, and theirs for him, also draws power from the Chaos Emeralds.
Super Sonic defeats Perfect Chaos handily, and the monster re-forms as Chaos 0. As he faces Sonic and his friends, many Chao emerge from the water and surround him. Tikal tells Chaos that the Chao he protected are living peacefully in Chris' world. At peace again, Chaos and Tikal rise into the sky and disappear.