Sword Art Online recently brought the ambitious Alicization arc with the final episode of the War of Underworld arc, and it teased fans with an ominous cliffhanger for an "Inter-Intelligence War" hinting at the "final" saga to come. The Alicization saga was the biggest undertaking for the anime yet as the third season of the series told this saga across four different cours of episodes. By the end of it all, fans were introduced to a completely new kind of Underworld that had advanced in many ways during the 200 years Kirito and Asuna had lived there.
But while this was already building to several intriguing questions for the future, the final moments of the Sword Art Online: Alicization - War of Underworld finale were far more enticing as it gave fans a tease for its next major conflict, the Inter-Intelligence War. The only problem here is, no one really knows what this refers to just yet.
The final moments of the episode revealed a few interesting key phrases with the following flashing on screen before it all came to an end, "This is where the story ends. But the battle continues for Kirito, Asuna, Leafa, Sinon, and the others, as well as for Alice. They will next take up their swords on the final, greatest battle of all, the 'Inter-Intelligence War.'"
As for when this war will take place, or what will potentially lead into it, the next part of the tease reveals that this final battle is quite a ways away, "But as of this moment, every possibility is but a faint flicker, wavering beyond a fluctuating light." This was followed by a tease that "Kirito will return," but there are several questions needing to be answered.
First of all, the "Inter-Intelligence War" has yet to break out in the original light novels of the series. The light novels are currently in the midst of the Unital Ring saga, and there is a chance that this "final, greatest battle of all" will take place but it's not quite clear yet. The teases in the finale show an Underworld that has advanced in intelligence and a virtual Kirito copy that is setting out to save the Underworld from being shut down.
So perhaps, Kirito and the others will eventually have to fight against his virtual self in the future? As technology advances in this world there will be other powers seeking it (as seen in the finale), so what do you think? What will the "Inter-Intelligence War" entail? Let us know your thoughts in the comments or you can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!