* He's already been the main antagonist: Mephiles played a significant role in Sonic the Hedgehog (2006), serving as the main antagonist. His story was somewhat resolved there, with his destruction and the restoration of time.
* SEGA's inconsistent approach to characters: SEGA has a somewhat inconsistent approach to bringing back previous characters. Some characters, like Shadow, have become recurring favorites. Others, like Mephiles, have remained largely absent after their initial appearance.
* No current plans: As of right now, there are no official plans or hints that Mephiles will be returning in any upcoming Sonic games.
* He's somewhat controversial: Some fans consider Mephiles a great character, while others find his story and motivations less compelling.
Potential for a comeback:
* New storyline: There could be a compelling reason for Mephiles to return in a new story, maybe tied to a different time period or dimension.
* Connection to other characters: He has a connection to Shadow, and if Shadow is involved in a future story, Mephiles' involvement could be explored.
Conclusion:
While it's possible Mephiles could return in a future Sonic game, there's no guarantee. His inclusion would likely depend on a compelling story that justifies his comeback and resonates with fans. It's ultimately up to SEGA and the Sonic team to decide if and how he'll be involved in future titles.