This is a double-edged sword: The impact is diminished, but you can fill your deck with creatures that have strong ETB (enter the battlefield) triggered abilities and reuse them
Of course, the only time this card may not be of use is if your opponent is playing the same creatures you are, but you can simply name any creature type not on the board, and it will function as a standard board wipe instead
That incentivises players to build highly thematic decks using evil Lord of the Rings cards
Silvallys at around $9.15, depending, and for the bones of a 10 dollar bill, you get the useful power of filling out your hand with five cards at the start of your turn, and a couple of hefty attacks
Be Prepared can reset the board if your opponent gets too far ahead while Maleficent is normally ink but can become a great finisher after you've cast Be Prepared and you and your opponent are both in top-deck mode