Sonic Battle: Story Mode Part 17 (Extra): Vs. Chaos (10 Story Mode Matches)
6In Emerl's Episode of this game's Story Modes, there's a bit more you can do than just fight Eggman. You can also fight every other character in the game to help Emerl gain more Skills and Skill Points, even Gamma!
However, there is one character that exclusively shows up in this episode: Chaos!
Knuckles has stated that Chaos is a water god and the guardian of the Chao, being a mutated Chao, itself. The reason it he has returned after Sonic Adventure 1 is due to a time of crisis, as in Eggman's newest Death Egg and Final Egg Blaster threat.
You can have Emerl fight Chaos at the Holy Summit's Crater. He hits very hard and can take a lot more damage than usual. The rockin' theme that plays is also exclusive to him rather than the stage you play against him on.
If you beat him once, you'll be able to use Chaos in other modes, and this will also be the start of Emerl getting Skills from Chaos as well, such as his hideously-slow Run Skill.
I take on this God of Destruction for 9 more matches before calling it quits. There are more things I can find and do only in Emerl's Episode.