One thing you might not realize from this card: cursed tokens deplete rapidly, and more rapidly when you have more in the bag.
As I’m writing this, this is the most difficult seeker upgrade to get, and we don’t know what it does. To get it, you’re going to need other decks not only having cards add curses to the bag, but almost certainly “tides of fate”. (Or you could play solo, but if you’re playing solo seeker you probably don’t have the extra time and actions to flood the bag.) otherwise, you’re going to be putting tokens into the bag while your teammates remove them, unless they don’t have any skill tests, or encounter cards… Which requires them to build their deck around this room grimoire anyway.
Unlike the seeker cards that require you to pass skill tests, discard cards, or fill your hand, This one negatively affects your teammates in a massive way, and undoes itself.
Hopefully the payoff is worth it! Because when you succeed, you’re still going to have five curses floating around in the bag.