The medieval Popes ruled directly over the Papal States in Central Italy, and was an influential player in the affairs of European states. The Dark Emperor of France set in motion a master plan to bring the catholic church under the French Empire's domain once and for all. He bequeathed a domain in the south of France to Pope Gregory X, enticing him to move his retinue to the city of Avignon. By enticing the Pope away from his historical home in Rome and centering the power of the church in France, It would open it up to be directly influenced by french emperors.
The plan hit a roadblock with Pope Gregory XI. Disgusted by the corruption of his blessed church and filled with the righteous fury of St. Peter himself, brought the Avignon papacy to an end by returning the court to Rome. However, following his death, an event known as the western schism took hold of the church, in which the cardinals refused to follow the direction of the newly elected Pope and elected another pope after returning to Avignon, setting in motion a rival papacy in the french city. This would lead to a succession of Anti-Popes, who competed with Rome for dominance and power. The anti-popes would eventually culminate in the formation of the "Dark Papacy", making them the center of power in all of Christendom and ushering in an age of terror across Europe.
In order for this future to occur in this timeline, I need the anti-popes to "win" against their competitors in Rome and for Avignon to eclipse them as the center of power permanently. How can I make this happen and make it stick for the long term?