User blog comment:RoniX2D/Why was Chaos included in Sonic Forces?/@comment-31555858-20171121195440

I heard the team came up with Team Sonic VS Eggman Empire idea when they were developing the game already. So they tried to get that "all-star" battle, that's why they included Chaos, one of the more well-known villains. Even though Chaos stopped being evil long time ago, just like Shadow. They then just said that we're dealing with just replicas. The developers probably tried to include them all as bosses but seems like Chaos just didn't get enough attention. I saw a theory about him being a boss planned for Luminous Forest, since the snake there appears with similar water effects and behaviour. That would make sense, but what we have now as a Luminous Forest boss is Infinite.