Ho' Ma' Utz

The artificial intelligence analysis of the mission profile calculated the crew's survival at fifty-fifty.
The crew of the Dugr thought fifty-fifty generous.
Finding the enemy who has pillaged the galaxy for three millennia is the easy part. Pillaging is a nice word. They have been killing millions for over 3,000 years.
The hard part? How do you stop a race of non-corporeal beings?

You fight dirty.

Fight dirty and win, or Earth becomes the next victim.