Izzet Delver is a fast clock with Dragon's Rage Channeler and Murktide Regent, so we want cheap interaction that doesn't cost us tempo. Force of Negation can be cast for free by exiling a blue card, but only on their turn, so it can't protect our own combo turn. Where it helps is answering their noncreature spells like Cori-Steel Cutter and Lightning Bolt without spending mana. It can't counter creatures such as Dragon's Rage Channeler or Murktide Regent, and on our own turn it costs a full three mana. Brazen Borrower's Adventure half bounces a problematic Murktide Regent, a Cori-Steel Cutter, or its Monk token to buy a turn. The 3/1 flash flier can block only creatures with flying, such as a Murktide Regent or a delirious Channeler, and it can also pressure or finish. Fatal Push is weak here since it can't touch a grown Murktide Regent, and a Cori-Steel Cutter equipment isn't a creature, so we trim it for more proactive interaction. Street Wraith is replaceable filler against a deck racing us on the clock.