Team Artificial Heroes. Metal Sonic (Speed), Shadow (Power) and Surge (Flight, via Electric Propulsion). I think there’s a lot of interesting things that could go on dynamic wise with these three, since their backstories are incredibly similar (created by Mad Doctor via questionable means that fuse the best of biology and technology, whether that be studying the biological to make a superior technological model—Metal—Using technology to create the “ultimate” biological creature—Shadow—Or using a biological base with technological cellular alteration to achieve the in between—Surge) and they all are within the greys of morality.
You could really see compelling interactions as Metal holds a grudge over his loss to Surge, the Tenrec herself trying to get by with her hate for Sonic (and thus Metal) as well as those who “allow Sonic to play” (Shadow), and Shadow trying to be what Sonic and Maria were to him as a guiding light to try and lead them onto the better path. You could even learn into their respective perceptions of the world—Surge is reacting to slights against her. Letting go of that grudge and focusing her negativity into good could truly redeem her. She could fully develop into the “next Shadow.” Conversely, Metal, despite having free thinking, despite being fully sentient beyond his encoded hatred and desire to become Sonic PERFECTED, CHOOSES his path because that is the objectively best way to prove superiority to Sonic. To cut out weakness (Emotion), to become even more self-sufficient (Be Alone), to channel every facet of himself into this singular goal (Giving Away His Freedom) to beat Sonic.
You could really and easily have an Infinity Train moment where after growth both seem to be a truly better path, only to reveal that Metal hasn’t changed. He’s done the heroism now, he’s saved lives. He’s been cheered on. It didn’t make him faster. It didn’t make him stronger. All it did was waste his time and save worthless lives. All of the “do-gooding” to him is merely attempting to save filthy, disgusting, inferior, absolutely revolting organic ants from inevitable and satisfying flood that was death, and distracting him from conquest.
Whereas as we’ve seen with Surge recently with the Phantom Rider, she loves being the hero, the awe, the celebration, the warm and fuzzy feeling that comes with doing good for the sake of doing good. These people may be temporary, and life might suck, but she can finally pick up what Sonic was putting down: There’s value and enjoyment that can be found in anything and everything, including life. She can finally enjoy freedom—True freedom, removed from the shackles of her lack of true past, the tragedy of her interactions with Starline, and live a life worth living.
Finally, the conflict occurs. The team shatters. Regardless of who wins, they will all look back at the time wistfully, even if it was destined to end and was doomed to fail since its inception.
Or it could be the total vice versa. Surge is the villain and Metal finally becomes the hero. Or they both become heroes. Or they both become even deeper villains, allied in their hatred of Sonic. And infinitely more possibilities. Interesting stuff.