User blog comment:Blitz0248/Where's Chaos and Zavok?/@comment-2202259-20171116143818

Zavok's probably alive & Infinite probably met him to create a Replica capable of actually having Zavok's personality & voice accurately for that Boss Fight. Chaos has never actually been explained after Adventure what really happened to him & Tikal. If you're wondering why Chaos doesn't have a boss fight it's because of Generations having the Perfect Chaos Boss Fight.

Now there are many fantheories for where Tikal & Chaos went. Some claim they went to the afterlife, others say they merely found a peaceful place that they could call home & raise chao, while another theory had them return to their own time. The 2nd & 3rd seem most likely, as Chaos would probably want to avoid humanity after what he did in the game, 3rd theory would explain why we only saw Chaos return & not Tikal.