This story is a sequel to From Your Most Grateful Admirer
Tirek and Discord's past has been entwined since before the two met on the streets of Manehattan. In fact, Tirek once knew Discord as the pony he hated most, the one that he believed to be the cause of his fall. That isn't the only connection they have though; something is coming to Equestria which both Discord and Tirek know all too well, and in preparation for its arrival, Discord has decided to make some special provisions, and have some fun along the way.
Revenge is sweetest when you can get it without feeling the slightest bit bad about it, and what better way to get his revenge on Tirek than this? Some forced existential alteration will cause some wonderful chaos and help him prepare for the coming danger.
He just hopes it isn't too late to save Equestria.