Super Smash Bros. Ultimate DLC: 9 Echo Fighters Nintendo MUST Add
3. Sonic - Metal Sonic
Besides his egg-shaped creator, Sonic's metallic doppelganger has remained the most persistent threat standing between him and enjoying a carefree life with his chums, and it just so happens that the dead-eyed machine is a perfect fit for Smash Ultimate's Echo Fighter template. As are Shadow and Silver, of course, but those two knock-offs are exactly where they belong as Spirit Fighters. Metal Sonic deserves better.
On the whole, porting Sonic's move set wholesale over to Metal would be adequate, the only necessary replacements being the former's Spin Dash, Spring Jump and Final Smash. A functionally identical charge attack that revs the jet engine embedded in Metal Sonic's chest would solve the first; removal of the spring the second, it's just the Final Smash that could prove to be problematic.
Short of designing a bespoke finisher for the character, the only alternative is to have Metal flit across the screen as Super Sonic does, only minus the transformation. Is that flashy enough? Not really, but if it means Metal getting a spot on Ultimate's roster, it's a worthwhile compromise.