The Great Aerie is one, obviously, while the other is Ten Wizards Mountain
Izzet Chemister itself cant be cast this way, and if Mairsil leaves the battlefield before activating that second ability, the cards exiled with that first ability are lost forever
Fraying Sanity's triggered ability counts the number of cards that were put into the enchanted player's graveyard during the turn, even if Fraying Sanity wasn't on the battlefield at the time those cards were put there, and even if those cards have left that graveyard
If you don't pretend to be surprised, you'll hurt Jadelight Ranger's feelings
All must be one, and while converting the populace into Phyrexians is one way to go about it, simply popping out more nightmares can be a quick and nasty way to build up an army
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