Players pick one card at a time and repeat this process until all cards are chosen
If you somehow can't discard a card (probably because you had no cards in hand and another effect prevented you from drawing cards), you won't put any counters on Cait no matter whether or not the defending player discarded a card or what that card's mana value is
Secondly, we can assume that the supply of Blue Ugin is likely to be lower than that of the set foil Ugin
So I eventually wound up with a 25-damage cohort of creatures, and Sauron equipped with The One Ring
With a bit of searching, it's possible to uncover better prices like the ones above
The lands enter play untapped, but you need to decide which color you will need, not just for the turn you play it, but for the following turn