The 3rd Reich is dropped into the modern world and is told to conquer it. If all the major nations united to make a giant modern military, could they win. The Reich start at their peak in the game and are given Germany to start with. How far would they get in taking our world over? And could we even do anything to counter them?
Let's drop the covenant and the flood, both at their peaks, into the 40k universe, the flood aims to assimilate everything while the covenant aim to conquer as many planets as they can, no alliances and both are immune to chaos. How well would they fair against each faction? Imperium of man, tyranids, tau, nurgle, slanesh, khorne, tzeentch, orks etc... could they achieve a fair chunk of their goals or are they annihilated?
Master chief vs space marine. Chief has full shields health etc... He can use any of the unsc issued weapons. He is dropped onto a field with a space marines, standard ultramarine, just a bolter and chain sword. How many marines can chief take before he goes down?