I respond with Jedi and Sith.

I don't really care what you respond with. I didn't post to argue about it, I didn't even say it is absolute that Star Wars would lose. I took the Jedi and Sith into account, including Darth Nihilus, who essentially ate a planet (all life on it). I also took into account the super weapons that the Star Wars factions have, such as the many Super Star Destroyers, the Sun Crusher, the Death Star I and II, and the Star Forge. However, from what I do know about the technology and abilities of the Forerunners and Precursors, I still think they have a better chance of winning. Also, the Flood. Imagine, the Flood infects a Sarlacc or Exogorth, assuming that is possible. And the Gravemind is working with the rest of the Haloverse. The Haloverse essentially has a ready supply of soldiers as the Flood infects the people of the Star Wars universe. What I really want to know more about is the "Infection" that occurred in Star Wars Red Harvest (I didn't read the Death Troopers, the book it is sequel to, and I don't know much beyond what little is told of it in Red Harvest), such as how it might fare against the Flood. But again, I still think the Star Wars universe has the capacity to win. Just a much smaller capacity compared to the Haloverse.

Star Wars has several Flood-like abominations that have risen up in it. Loose these abominations on the Halo universe? They wouldn't stand a chance. Also, I've read Red Harvest, and they're a lot like the Flood, except that they don't stop even when you destroy them. I don't want to spoil anything, but one of the characters gets killed simply by a head. Lol, kinda funny, but damn. Also, [quote]The Haloverse essentially has a ready supply of soldiers ...[/quote] the star wars universe has a machine that pretty much builds an infinite amount of military combat-ready equipment, such as droids like HKs, and SSDs, for example