In honor of the new year I'm going to spoil a bit about the story's upcoming confrontation.
Ben 10, Akumasa vs Black Caster.
Khanh Minh vs Red Acher (AKA: Atalanta alter).
Kamen Rider Geast vs Anos.
Mihawk vs Sieg vs Karna.
Jeanne and Ruler vs Red Assassin.
Chiron and Frankenstein vs Anos.
Sieg vs Astolfo.
Artoria and Mordred vs Caster red and a a special person.
Those are the fighting pairs that will appear in the final battle after the work of the black Assassin Jack The Ripper, and will have the advice of two people, Ben and Geast, and also appear with the user of Ultra Instinct and the power level upgrades of weapons, especially Sieg will have a bigger change than Fate Apocyphal.