Let’s take to alternate versions of the Star Wars universe and the DC Universe (earth prime).
These universes are exactly the same until a certain point in the timeline with the two universities somehow collide with each other (except on this Version of earth prime, George Lucas has never created the Star Wars franchise so The green lanterns of earth would not get any of the references of Star Wars in this battle.)
The green lanterns are Patrolling space when several new planets appear out of nowhere in space. These planets are from the Star Wars Universe. (The Base World of the Jedi Order and Galactic Republic Capital of Coruscant would Appear right above Oa, The base of the Green Lantern Corps and the guardians of the universe.) The guardians send several green lanterns To investigate this new mysterious planet above them and the Jedi Council also do the same thing sending several Jedi Knights as well as various clone troopers to investigate this new planet above them.
How does the scenario Play out and how does it end!?