At this point I swear Sonic hates the Deadly Six way more than Eggman...

Why is chaos considered a rival? He’s been dead for years and the most he’s done is flood station square.

^ Chip too but he's here too

I mean at least Chip talked and got to really bond with Sonic. I see no reason for Chaos of all characters to get the label of rival

Wait didn't Chaos come back in Sonic Battle? Does he have the ability to come back?

I don't think his appearance in that game is canon. I'm pretty sure he's been dead since SA1

Sonic Battle is 100% canon, simply because of Emerl's appearance in the Dark Beginnings anime. Chaos also reappeared in the Sonic Channel comics, aka where main canon Sticks made her debut.

I meant Chaos's appearance isn't canon since I don't think he ever appears in the main story

I could've sworn that was a required mission for the story, but still, Chaos isn't dead and the Sonic Channel comics are the proof. Seriously, they were the original place where Maria gave the explication to Shadow's name. They're absolutely canon.

I just looked through those comics and is this the comic you're referring to cause this is most likely set during the past