Legitimate cards have a consistent, high-quality print on the back, including the iconic Pokemon logo
Card not found was a major player in Standard for a while and has made appearances in pretty much all Constructed formats, including some play in Vintage
Balance of Judgment - A table flipping card that you learn to love and hate
Basically, theyre hard to balance, like planeswalkers, except they have to do even more because they wait a turn to do it and theyre harder to interact with, all of which sounds pretty dangerous to me from a fun standpoint
Because of the "different" names restriction, this is best in Highlander and Commander style formats with one-of anyway, save for basics
It's one of the reasons milling isn't as strong, it takes longer to kill someone, and they are likely strengthened by it