War of Realities.

Prelude
Before the war started, Palpatine spoke with the new Grand Inquisitor. Palpatine sensed a disturbance in the force. The new Grand Inquisitor felt it too. They sensed various realities being destroyed.

The War
A portal opened and a large warship came through. The Supreme Hunter was on the warship. He was going to destroy the entire galaxy. His army of Hunters began stealing valuable items. Palpatine ordered his Empire to fight back. The Hunters fought back harder. The Supreme Hunter left his warship so he could personally destroy his enemies. The new Grand Inquisitor was almost defeated by The Hunters. The new Grand Inquisitor was saved by an alternate version of himself. The Supreme Hunter left the galaxy.

Post-War
There were many casualties during the war. The war only lasted for two days. The new Grand Inquisitor never returned. Palpatine decided to build a second Death Star so that the Empire would be ready if The Supreme Hunter ever came back.

* This is not a crossover