The Emperor of the Night is the main antagonist of the 1987 animated film, Pinocchio and the Emperor of the Night, who was a secondary player in the Disney vs. Non-Disney Villains war.
Disney Vs Non Disney
A Deal With Rasputin
Although not shown in the videos, in the Fanfiction story, he is seen discussing a threat in the form of Chernabog, with his ally, The Nightmare King. It isn't long until Rasputin arrives, as Rasputin attempts to forge an alliance with the powerful beings. The Emperor of the Night contemplates Rasputin's offer, until Nessus intervenes and attempts to attack the Emperor. Rasputin, however, fends off Nessus, and, as a show of gratitude, promises Rasputin a favor in the future.
Pre War: The Demon Lords
The Emperor appears as one of the three demon lords. He and his brothers, Chernabog and the Nightmare King, have created a powerful crystal in which all heroes would die, and evil and chaos would reign through the world. The Emperor and the King are caught off guard as Chernabog wishes all the power for himself. However, as the crystal displays it's amazing power, wiping the globe clean of all that is good, The Dark Council appears and detsroys the crystal, much to the Emperor's secret dilight.
Revenge against Chernabog
During Chernabog's massive battle against Rasputin and Rothbart, the duo found their powers incapable of defeating the mighty beast. The Magic Mirror displays the Emperor of the Night as a being that can put an end to Chernabog's terror, and Rasputin decides now is the time to use the favor he was promised. The Emperor of the Night appeared and made good on his promise, as he used his powers to vanquish Chernabog, gaining revenge on Chernabog for his betrayel from before the war.
Vs Hades
The Emperor is later challenged by Hades. Hades throws a mighty fire ball at the Emperor, who struggles from the attack before using his magic to coat Hades in ice. Hades, however, turns the tables on the Emperor, and uses a spell given to him by Eris to shoot a large blast of lightning from his hands, draining the Emperor of his power and banishing him to his own realm.