The flexibility of exiling key permanents such as Amulet of Vigor or Aether Vial is extremely relevant in a format as diverse as Modern, and many decks are even opting to splash an additional color by adding off-color Shocklands or Tri-color (Triomes) lands to their mana base, so they pay an additional color for the converge mechanic on Prismatic Ending
If you have all of this put together, you can cast infinite copies of Dramatic Reversal
Elesh Norn, Mother of Machines Part big creature, part Panharmonicon
Three Visits is mechanically identical to Natures Lore, a card you can pick up for a couple of bucks
If a triggered ability asks you to pay a cost, you pay that cost for the copy separately
Thats the trick with Zur the Enchanter, a classic combo commander that grabs any enchantment with mana value 3 or less right from your deck