Aww man, RIP Bind of Isaac placeholder. I was cracking up over the juxtaposition of your game versus the bloody background.
I'm loving the character and item designs! Just looking at them builds an image of what the aesthetic of your world might be! Especially the Cloud Mage.
I was going to suggest an idea for a solution for the random shop name problem, but I'm not familiar with python. You might try keeping a list of the random shop names you've used already and check against the new random shop name you're getting. But I think there might be a more elegant solution such as removing used random shop names from the function that's giving them, or something like that. That's more complicated I think though.
Keep great work flowing!