Occurring in the same time in both universes, there are two scenarios. 1) Cosgrove reconciles with his friends from the Circus and 2) Sunset Shimmer starting small outside of the Mane Five
When Cosgrove accidentally reveals Schnookums to the Crusaders, Princess Luna gets word and conflict ensues. Cosplay must prove that Schnookums is not the same Brobdingnag or he will be placed far worse than Tartarus