Exiling removal is great, and most of the creatures you want to kill at the kitchen table meet the requirements
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
However, a card with a good grade can turn a great profit, whether a collector looks to sell it immediately or in the future, when the cards value may rise even more
The dual land cycle includes ten lands, each of which represents a different mana colour pairing
Deal 1000 damage to your opponent
A Genesis Hydra for four was absolutely fine for the mid-game, and a Genesis Hydra for seven was similarly excellent