Board Thread:General Discussion/@comment-2055856-20160708073759/@comment-24830601-20160712035949

Time Eater was able to attack Crisis City because it's not a timeline that's "supposedly gone", it's just an alternate timeline. Whenever time is manipulated, it always creates new timelines containing what the future would hold if time hadn't been manipulated. Time Eater has the innate ability to consume all of time, similar to Solaris, meaning he can travel through timelines that were meant to have been non-existent. The reason for bringing back Crisis City, I don't know.

As for the Ilfrit, yes, Silver's future was meant to burn due to the actions of the Ilfrit. Since 06 was removed from the timeline, Silver came back in Sonic Rivals fighting because of the Ilfrit's actions rather than Iblis'. Silver's future would be burnt regardless. Even still, they saved the day and all that, and in Sonic Colors DS, Silver says the future is happy.