Three of them, Goblin Warrens, Goblin Assault, and Goblinslide, provide us with goblin tokens that serve as cannon fodder
The set featured vampires as one of its main tribes, featuring important cards such as Anowon, the Ruin Sage, Drana, Kalastria Bloodchief, Kalitas, Bloodchief of Ghet, Butcher of Malakir, Malakir Bloodwitch, Nirkana Revenant, Vampire Nighthawk, Blade of the Bloodchief, among others
Cards like Aetherworks Marvel are a great payoff, letting you cheat out cards from the top of your library for six energy counters, while Gonti's Aether Heart can grow your count more and give you an extra turn
This is why the removal in the deck is so expensive, you need it to do a lot of different things and well, you can afford the extra mana but you cannot afford to have a removal spell that doesn't kill a couple of their threats
Check out these two 1/1 two-mana Druids
Basic snow lands are great and get the job done for the most part, but you absolutely need a more varied mana base in formats like EDH