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Hi, I'm a european crested tit, and a very small punk rocker!
Is there a rough estimation of how many sleeves they will need just to protect the cards that get shuffled?
Uuuuuuh there is a comprehensive list floating around in the base game's forum.
Typically it's 9 cards per Nemesis + eventually his deck (with the exception of Blight Lord's and Crooked Mask's as their cards get in YOUR deck.)
Then the basic Nemesis cards, I don't know how many there are.
I sleeved everything and I don't even know how many cards that is so someone else will help you better i hope