Sen Triplets Sen Triplets is an obnoxious Esper card to play against if left unchecked, as itll steal resources and wont let you interact with them on their turn
How is it in-game
On top of all that, she also has a solid five willpower and can quest for two lore (or turned into ink, if you prefer), making her a very adaptable card
It also frequently summons actual vampires in its armies, a second iconic creature type to complement its endless hordes of zombies
Not background necessarily, but some other line of text that says something along the lines of Whenever you sacrifice a Treasure token, give a creature a +1/+1 counter and trample until end of turn. That would make it a lot more interesting and powerful, but I suppose not every card needs to be great
As some people pointed out, there are still potential workarounds to the limit, although it won't be as easy as just grabbing the entire stock and checking out all at once