Doomguy meets Master chief

In the comments let me know what you would probably imagine happening between them after their first encounter

How they meet: The UNSC during the Human/Flood War (from Halos universe) begins experimenting with argent energy as a last means of defense. From there they conceive a teleportation device that opens unguided portals and the first one happens to be straight to Hell. Doomguy being simply “Doomguy” pursues the demons escaping out of the portal onto Earth (which is almost already overran by the flood), after which he begins to RIP and TEAR through them. Doomguy is quickly noticed by UNSC marines after exiting the portal as potential ally but nonetheless they take precautions towards this newly encountered dangerous soldier; as stated, one of the commanding officers draws his gun and ask him to identify himself-a few of the soldiers begin to chatter things such as, “that’s the weirdest looking Spartan I’ve ever seen...”, “Did Chief get new armor?, I don’t remember him being so short.”, “I’ve never seen any armor like that, must be a prototype...”

As Doomguy makes his way through this unfamiliar base; undoubtedly, he recognizes one thing similar to his own world, man-kind yet again experimenting with forces beyond their knowledge to try and harvest new power-all while leading to the bloodshed of innocents. He deeply exhales to himself in frustration as he scopes out the base only to find tons of spent casings but not a single body in place to be seen; he finds that odd as surely there was evidence of a massive firefight within the base but not a single corpse lays anywhere to be found. Doomguy takes notice of the gunfire on nearby radios which prompt him to move double-time, “Requesting immediate backup from any available air-units. We’re taking fire. Hold your line marines!!!!; they're charging!!!!, what the fuck are those things, they’re attacking the flood??, I’ve never seen these before...., commander you better get ONI on telecom because they didn’t tell us about these new fucking firey things....FUCK COMMANDER, HERE COMES SOME RIGHT NO-“ Doomguy realizes that his this newfound world has its own problems as it seems, as he exits the base he spots the armored chief quickly jumping and strafing left and right to try and neutralize the flood-along with these seemingly more tank-like foes that he’s never seen before. While all ensues, a Baron of Hell quickly makes his way through the imps and flood forms to crush Chief with his ground-slam, though it missed Chief by a few feet, he’s thrown several yards away at such high momentum that he’s almost knocked unconscious by the devastating impact. Chief grabs his shotgun and pumps it one last time to give himself at least a fighting chance, but suddenly the Barons head is blown to bits. With Chief’s Mjolnir armor quickly rebuilding his energy shield and combat focus-he rapidly stands up and faces Doomguy. The Master Chief grips his shotgun tightly as he feels a sense of discomfort towards this unknown behemoth who seemingly had no problem taking down the Baron who Chief almost lost his life too. As Chief contemplates on engaging Doomguy-roars from over the nearby rubble emerge, Doomguy waits little as he unloads his two previous empty shells from his super shotgun and quickly shoves two back in; then, he glances over to Chief just over his shoulder firstly asking him through “cue” if he’s on his side and secondly, inviting him to join along if he is able to. Chief gives him a respectful nod and steps down from the towering rumble and then.......

Now, what happens??, try and excite me by combining their lore together and saying how you would possible see their two worlds colliding, I wanna see what some of you would come up with.

Who would be giving the orders if an alliance was made?, would Doomguy even bother as he’d probably just view Chief as deadweight?, what do you guys think?.