Pitch Black versus Aliens.....
The Raptor creatures from "Pitch Black" (The entire horde of them, let's guesstimate there are a thousand of them, fully grown) decide to make LV-426 their new home. Little do they know that inside, reside the Xenomorphs from "Aliens."
The Xenos are prepared, as the Raptors near, the Queen sends out her soldiers to engage them. Let's say there are.......600 Xeno soldiers, all fully grown, all ready to die to defend their queen.
The Raptors must fight past the Xeno soldiers, kill the Queen, and claim LV-426.
The Xenos must defend their home and queen against the Raptors.
The fight takes place outside the complex.
Who comes out on top?
BTW, if my numbers of Raptors/Xenos is out of whack, feel free to suggest a fairer number.