Who is 'Mephiles the Dark'?

Amongst the many battles that I fought during the Time-Eater crisis, one particular battle sticks out to me. The one battle against an adversary which I had no prior memory of...

Mephiles.

Who is he? Why does he look like me? What kind of faker is he?

Why is his name so stupid sounding? How would you even pronounce it? Meff-phillies? Mee-files? Meh-fill-is? The possibilities are endless.

Why is his voice kind of sexy?

Why is he goopy like that?

I feel like I can sometimes see flashes of him in the corners of my mind... but I don't understand why...

Are these memories a mere delusion? Or are they fragments of a greater whole that has somehow since been erased?

Much to ponder...

- Shadow the Hedgehog, aka Ultimate Lifeform, aka Superior Protagonist