Guild Wars 2

I’ve googled, but all I can come up with is stuff about stronghold NPCs, and nothing about the skins and what to do with them.

I think they are in fact the Mist Champions with different looks, ie skins. Buying the skin gets you that variance on the Champ look in Stronghold. I don’t know if they have different skills to go with the skins or if it’s entirely cosmetic, as I have not yet played Stronghold other than one beta round before the skins thing.

Are the skins used to unlock the Champions?