While a bit contradictory with the Amethyst portion of the deck, which has you constantly sending characters back to your hand, if you keep bringing them to the field , your opponent may be put in a difficult situation, unable to use Actions if you play your hand right
If you have an optimal opening hand, you can drop an Ancient Tomb, get two generic mana, drop a Sol Ring, giving you three generic mana, and drop practically any other mana rock or spell you might want for three mana
While the effect itself is powerful, its limited severely by its casting requirements
The way a Battlefield turns around as soon as this Creature goes Monstrous is astonishing
Every time you cast a creature, you draw a card and put a land into play, which essentially fuels itself, especially with cheap enter the battlefield creatures or mana dorks
It can also attack pretty well to trigger Tymna, and for that reason, it could well see some play