Going straight from 3 mana to 6 the next turn after you play a land lets you rocket out some terrifying beaters like Hellkite Tyrant and Ancient Copper dragon quite early, and you can run blacks cheap graveyard tutoring like Buried Alive or Entomb to gain easy access to a variety of threats
With enough self-mill effects and lands with potent abilities, such as Field of the Dead, youll gain an enormous advantage from this exchange
Now, like Eureka or Living Death or other similar, Mass Enters-the-Battlefield abilities, you often have to deal with a ton of triggers, so it can take a while to process
0: You draw a card and lose 1 life
Creature keywords are simple and easily graspable, thus allowing us to spice up these cards without adding to the perceived complexity
Bear in mind, though, that it's extremely difficult to protect cards from fading or sun bleaching if they're on display