Seriously, how are you supposed to fight these guys?

I usually play all stealth so my loadout is not very offensive, so when I encounter these guys I just finish they objective, call the chopper and book it.

Do you basically need a machine gun and a grenade launcher? I heard it's possible to fulton them but wouldn't that need like 50 tranq darts per Skull?

It seems like a demanding task -- the second (sorta) boss (in chapter 11) only took about 6 or 7 tranqs to take down non-lethally... I don't think you can CQC skulls either, I just murdered them the first time, they don't technically die if you do "kill" them anyway, they just get back up and just warp away as the mist disappears, killing them seems to only be worth it for the sub-objective.

I wonder if you can replay the mission with better non-lethal gear and retroactively Fulton them... hmm, I might give that a go.

Sleep grenades/mines are your friend.

Do those grenades actually knock them out or are they only stunned for a while?

A single grenade won't do it, in my experience it takes two, but once they're down they're out. You can tell by the stamina meter that will deplete. (the one under their health bar)

That's awesome, now I just wanna get back in again

I haven't fought them at all yet. In the very first mission you encounter them I managed to stealth past them (at the bridge). The mission in the quick look was won by me getting on D-Horse and booking outta there. The boss in Mission 11 got a supply crate to the head.

I'm not sure whether it's possible to CQC them in a normal fashion, but you can counter their melee attacks for spectacular results. It involves gutting them with their own weapons and then just ripping them wide open. It's a hell of a thing, and you should go out of your way to have seen it.

Ontop of that, I found local gun emplacements such as LMGs to be extremely useful. If everything else fails, lure them next to a red barrel. They're either colour-blind or just plain stupid.

@khessed: I had to ride past them and they chase you all the way to the chopper. every time I try to sneak past them they see me!

@mrswift: what I did was, I got under the bridge from the right side. After a bit they come down and i went back up from the left side. The guys on the right come down first, then the left.

After both groups are under the bridge you can walk over the bridge to the other side and call D-Horse to get away from the situation without an alert.

@khessed: thanks I'll go back to it go for the S rank.