Sonic: Metallix Unleashed (169361) : BlazingZtar755 : Free Download, Borrow, and Streaming : Internet Archive

A Sonic the Hedgehog fan comic which features Metal Sonic as the primary antagonist. Credit for sprites where it is due. May feel somewhat generic.

Metallix, Sonic the Comic Wiki

Sonic and Eggman (7671) : Darkblade128 : Free Download, Borrow, and Streaming : Internet Archive

Sonic Unleashed : Matthew Paul Argall : Free Download, Borrow, and Streaming : Internet Archive

the steel, the mist, and the blazing sun : Free Download, Borrow, and Streaming : Internet Archive

Metal Sonic in Sonic the Hedgehog : Lone Devil : Free Download, Borrow, and Streaming : Internet Archive

Metal Sonic in Sonic the Hedgehog : Lone Devil : Free Download, Borrow, and Streaming : Internet Archive

Sonic and Eggman (7671) : Darkblade128 : Free Download, Borrow, and Streaming : Internet Archive

Sonic 1 Metallix : Free Download, Borrow, and Streaming : Internet Archive

Sonic in Paynt : sebmal : Free Download, Borrow, and Streaming : Internet Archive

Sonic: Metallix Unleashed (169361) : BlazingZtar755 : Free Download, Borrow, and Streaming : Internet Archive

DUB] Sonic X Vol. 6: Countdown to Chaos : TMS Entertainment; 4Kids Entertainment : Free Download, Borrow, and Streaming : Internet Archive