Epic cards will fall in between the previously established Legendary and Enchanted rarities , being more rare than Legendary but not as hard to find as Enchanted
Seeing as you had to trade your Haunter to evolve it, Gengar wa a rare commodity in the mainline games
But how did Paul manage to get his hands on such a rare card
For just 1 white mana at instant speed, you get to search your library for any artifact (or enchantment), reveal it, and place it on top of your deck
It's also why they're immune to the poison status effect
Something along the line of a scannable code on cards to verify authenticity would get the job done, but implementing the program would be costly, and it wouldn't help with all the cards that are currently in print (barring some sort of mass-exchange program, which would be even more prohibitively expensive)