Altisaur Caravan

At the beginning of your upkeep, put a journey
counter on Altisaur Caravan.
When Altisaur Caravan enters the battlefield,
exile the top card of your library. As long as it
remains exiled this way and you control Altisaur
Caravan, you may play that card. Its mana cost is
reduced by {1} for each journey counter on
Altisaur Caravan.
Reach