Wilson

None of these have a chance. SPARTAN IIs are too few and have less experience, Cylons are just canon fodder, the Covenant is one virus bomb away from shattering and the Terrans are discount Astartes. None of these factions have the numbers to even take on the more likely opponent which would be the Guard.

Like people don't get the Imperium fights on an hourly basis with factions 10x worse than all of these opponents plus the other obvious ones like the Empire. Hell 1 space marine chapter sacrificed itself to battle through the Necron equivalent of the Death Star, destroying each generator and command node till only handful were left that took out the command bridge so the Imperium fleet destroyed the station with planet killing torpedos. Its that level of extreme the Imperium brings that I doubt any faction here can match from Star Wars to Marvel. The Imperium is a force of trillions from random PDF units to the Guard to the Mechaicum and all the other militant forces to include the Space Marines and offshoots like Grey Knights and Deathwarch. It's an endless wave of murder hobos led by demigod murder hobos that fight on an hourly basis against other murder hobos