Hello! Someone used xenoskulls? ... how to use them and which missions?
Starting operation strikeback soon.
I haven't used any of the KS2 stuff yet either. But I believe that the Xeno Skull is just extra KS exclusive stuff like the Xeno Morphs (Aliens) from the first KS. And if that is the case the only time you would actually need them is in the scenario(s) that is(are) explicitly designed for them. In the Xeno Morphs' case that is only the online scenario and nothing in the regular campaign.
But you can/should feel free to replace any aliens from a campaign mission with the Xeno Skull as you see fit.