There are tons of extremely powerful effects that become even better when doubled up, like Portal to Phyrexia's ability to force your opponents to sacrifice three creatures when it comes into play, now forcing all your opponents to sacrifice six creatures instead
Growing a board for very little investment rocks
Over three turns, you can hopefully generate one mana, create two Constructs, and tutor a Sol Ring, Shadowspear, or Skullclamp straight onto the board
Sidar Jabari of Zhalfir, Order of Midnight, Haakon, Stromgald Scourge, Knights' Charge 4 graveyard recursion
Tomb of Horrors Adventurer | Illustration by Irina Nordsol Initiative is a designation mechanic similar to monarch that allows players to venture into the Undercity dungeon each turn while they have initiative
Then, you'll want to down into the nitty gritty and take a proper look at the full decklist