oof yeah that seems pretty hard. I might make "boss" enemies not receive any stickers in the future.
On the other hand, thorns are a good hard nerf to over-reliance on fury - this run used the "female pirate who gets fury every time there's an 'on-death' effect" card, which is powerful if it can survive a round of deaths, but is nerfed by thorns.
I think that's a good thing in some way because it breaks the strategy of "sacrifice down to 7 cards and draw the same hand every game" and maybe encourages more diversity in card choices?