Board Thread:General Discussion/@comment-1031724-20160901000706/@comment-1031724-20160903152111

That's just so you can fight him again. Canonically Sonic only does each level in the game once (not counting previous games of course). Twice if you count Classic and Modern Sonic. Besides, you can also revisit levels in Bomberman 64, when it's clear he only does each once due to the deaths of Artemis, Orion, and Altair, and once you unlock Rainbow Palace, the Sirius you encounter each level (aside from the final) is a robot, and Sirius no longer gives you remote controls to fight the big bosses. So they changed it even though there's no way Bomberman could have canonically gone back there, both games let you replay the level as many times as you want.

There seemed to be nothing left of him in any event, but as I said, Eggman could always build another identical Metal Sonic if they ever decided to use him again.

But I didn't come here to debate another villain's fate. If Sonic 4 Episode I isn't set before Sonic CD, then what's with the apparent "grand introduction" of Metal Sonic at the end?