Thread:Ultrasonic9000/@comment-26194462-20150311233029/@comment-4220590-20150425190005

Well, Eggman said Solaris existed in the past, present, and future. I am not sure how exactly how widespread that means, but I suppose that story-wise, Solaris thus exist in three points in time simultaneously. Then, for the concept to be more comprehensible to the player, the game has Sonic, Shadow and Silver each fight him in each of these three points.

I can't really confirm this, but I am taking regard to both Eggman's statement and how the gameplay was laid out, and that is what I have come to.