They just have to put them in a separate pile and it's up to you to represent them
Add fun things like Magus of the Abyss, Dread Return, and Fleshbag Marauder and all his rude, rude cousins
Yes, a lot of their cards will be better than Shock, unless you were playing Limited back then in which case they might not have any such cards, but better enough
1 Altar of the Pantheon
At the beginning of your end step, if you didn't play a card from exile this turn, create a tapped Powerstone token
I think I may try it at some point since my environ lacks the sweet card draw spells many of you run (ie Thirst for Knowledge and company, which I can never seem to cram in), but I'm just not sure how often it would actually see play