Kaya's last ability checks to see whether the permanent was an Aura when it last existed on the battlefield, not whether it is an Aura card in exile
-Treasure Map, One of Ixalan's signature double faced land cards which, when flipped, enables you to turn all of your treasure tokens into card draw
Aside from a weakness against flying, its able to mobilize an army with frightening speed, and it grows with your aggression
Like most Magic: The Gathering cards, the value of Mountain depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (New Phyrexia)
You might as well get value from your ability before the removal spell hits, though you have to account for summoning sickness
It's confirmed that in this deck, you'll receive borderless Commander cards for each hero, not just one