The New Warriors, Vol. 1 #11A (1991)

Forever Yesterday, Part One: Days Of Present Past
The world has changed overnight, and nobody knows it. The New Warriors don't exist, and the superpowered individuals are either Avengers (led by Captain Assirya) or Mutant Liberation Front (led by Magnus.) Nova has doubts, and a visit from Sayge cements them.
Release Date: 1991