So every Jedi and Sith working together using the force along with every droid, battle droid, and jar-jar Binks against the entire Universe of Halo. Are we counting Halo books too? If we are counting books then this could be tough. I suppose that because the Death Star can instantly destroy planets at will, I might have to go with Star Wars but it's not my final decision. Chief has been able to take down thousands of enemies in a matter of hours. If we include the other Spartans (you said everything so I'm counting living and dead characters) that means that Halo could have a fighting chance on the battlefield. Now because Star Wars has a lot of space warfare, we need to consider how Halo could stand a chance out in the dog fights of space. If you've played Battlefront 2 then you know that you can deal a massive amount of damage to the enemy ship by simply walking inside and destroying it from the interior. Simple job for an elite to go invisible and destroy the shield generator using an energy sword. After this, the Halo universe would have to manage to destroy Life Support, and then would be able to destroy the Imperial Star Destroyer. The Death Star is a whole other story. Depending on how they want to handle it. Either by fighting from the inside out or by just shooting a couple of missiles down a shaft. They could take it down with a bit of a struggle but it wouldn't be tremendously hard. I suppose that this could end either way. They are almost evenly matched.