While the library function is expensive, the first ability works disgustingly well in tandem with a wide variety of blue and black cards
If a player suspends a card with a high mana cost, the game will look entirely different by the time it can be cast
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 (March of the Machine)
Even if the enemy manages to deal with them, the Thinking of You ability turns their defeat into a massive advantage by sending all involved cards straight into the user's inkwell face down and exerted
This can be extremely disruptive to decks that need pieces of their combo to activate from the graveyard
They can swing or join your sacrifice engines