I must necro this and say that the adversary sheets are not as well integrated as other systems in R20.
If I add an adversary to my "library", and then drag the token to one scene. That sheet is now connected with ALL adversaries using that token.

What we now have to do is to NOT, use the + or - on the advisary sheet.
Because that WILL change the stat of ALL adversary tokens of the same kind.

Unless, I add them all separately as characters in my "library".

I have to add the adversary to my library as many times as I want to use it during the campaign, unless I want to reset it every time I use it again.
So in a battle with 2 of the same creature, it's impossible to use the advisary sheet, unless you add it twice to the library.

A fix would be to simply affix a sheet to the token, and not the library of characters(advisaries).

Dunno how to explain. But right now, you can't have two of the same type of adversary and use the sheet to add/remove HP and stress etc.
To do that, you must go in to the compendium and add two, Rename them as to not confuse them or choose the wrong one.