Guild Wars 2

So where does this skin come from? PvP maybe?

Wiki says this comes from AP chests but 5.5k later I have never seen it as a choice. The next boxes that have the zenith skins in them do not have the pistol listed either. I have wanted this skin for a long time and have had to choose other things instead so far. :S

All Zenith skins are only from the AP chests.
If you don’t see the skin (make sure that you scrolled down the list till the end), that means you already have it.
If you don’t have it and also doesn’t show in your list, then send a support ticket because it is a bug.

The little popout message you get when you hover over it doesn’t show them all. It has an elipsis (…) in the lower right corner to let you know there’s more than what it’s showing.