Ever since his encounter with Sonic in Blaze's dimension, Nega has been traversing the Cosmic Interstate, causing mass devastation to every universe he has encountered thus far. His actions attracted the attention of The Zone Cops, beings from a perpendicular universe that maintain order throughout the Multiverse. The Zone Cops and Nega have been at war with one another ever since.
As a result, the Cosmic Interstate is now in ruins and closed off to everyone save for the Zone Cops. However, Zonic the Zone Cop's most recent report to Warden Zobotnik suggests that Nega is on the winning side of the war and that if he is not stopped soon there might not be a Multiverse left to save.