The final boss in Chaotix is a giant, red, demonic looking transformation of Metal Sonic.
The battle against it begins with a scene of Metal Sonic collapsing at Robotnik's feet after a prior battle in Newtrogic High Zone. Robotnik uses a device to transform another Special Ring into a Dark Ring, and beckons Metal Sonic into the ring. The screen flashes, and the player and partner are dropped into a cyberspace arena (10 rings already in hand) with the new monstrosity looming over them on the right. Despite its new power, it makes no attempt to utilize its size to attack besides an occasional slap with its now-detachable limbs. Eight hits to the shoulder knock one of the offending appendages off of its body. It then hovers behind the arena, using its remaining arm to try to crush the player. The player simply needs to attack the arm after it misses the player to damage it. Eight hits on this arm disposes of it as well. Metal Sonic then moves to the left of the arena, firing off its chest laser. Although Vector might see need to duck, the player can stand under the laser until it finishes firing, then jump at the chest to take down Metal Sonic and finish the game.
Should the player have collected all six of the Chaos Rings, a scene shows them floating around the word "COOOOL" followed by the good ending. Otherwise, the collected Chaos Rings are destroyed and the bad ending shows Metal Sonic, in the form from the previous battle, hovering menacingly over a burning city.
In Other Media
This version of Metal Sonic played a major role in the British Sonic the Comic, with a somewhat different design, under the name Emperor Metallix. As the leader of an entire army of Metal Sonics (the Brotherhood of Metallix), Emperor Metallix featured in a number of story arcs, operating out of Robotnik's abandoned base in the Special Zone. Its most audacious plan involved eliminating its former master from the timeline by retroactively preventing the laboratory accident that created Robotnik from Ovi Kintobor.
| Characters in the Sonic the Hedgehog game series
||Sonic (Super, Hyper, Darkspine, the Werehog, Excalibur) | Tails (Super) | Knuckles (Super, Hyper) | Amy Rose | Cream | Big | Blaze (Burning) | Emerl | Silver (Super) | Marine | Lumina Flowlight | Chip | Shahra | Knights of the Round Table | Caliburn | Yacker | Sticks | Avatar
||Shadow (Super) | Rouge | Espio | Charmy | Vector | Mighty (Super) | Ray (Super) | Chaos (Perfect) | E-102 Gamma | E-123 Omega | Bean | Bark | Jet | Wave | Storm | Shade | Merlina
||Dr. Eggman | Metal Sonic (Rocket, Neo, 3.0) | Mecha Sonic (Super) | Fang | Witchcart | Battle Kukku Army (15th, 16th, Dr. Fukurokov) | Tails Doll | Metal Knuckles | E-Series | ZERO | Void | Biolizard | G-merl | Eggman Nega | Black Doom | Angelus | Iblis | Mephiles | Solaris | Erazor Djinn | Captain Whisker | Johnny | Master Core: ABIS | Ix (Super) | Dark Gaia | King Arthur | Orbot | Cubot | Deadly Six (Zavok, Zazz, Zomom, Master Zik, Zeena, Zor) | Hard-Boiled Heavies | Infinite
|| Sonic/Heroes | Rose | Dark | Chaotix | Babylon
|| Gerald & Maria Robotnik | Froggy | Chao | Omochao | Cheese | Chocola | Vanilla | Tikal | Pachacamac | E-101 Beta | Illumina | President | G.U.N. Commander | Elise | Duke of Soleanna | Coconut Crew | Vikings | Professor Pickle | Wentos | Don Fachio | Heavy and Bomb | Tiara Boobowski | Honey | Flicky | Animals | Wisps