Izzet Prowess is a fast aggro deck that tries to kill you on turns 2-3 with pump spells and prowess triggers before you can resolve Living End. Your primary goal is to survive long enough to cycle and cascade — a resolved Living End almost always wins the game since you're bringing back 4/5 and 5/6 bodies while wiping their board. Force of Vigor answers Cori-Steel Cutter, which is their most dangerous threat because it generates card advantage and grows their creatures each turn. Dismember and Dead // Gone give you cheap interaction to buy time against Monastery Swiftspear and Dragon's Rage Channeler on the early turns when you're setting up your cascade. Wistfulness and Sink into Stupor and Brazen Borrower come out because they're too slow or insufficiently impactful in a race where every turn matters; your Force of Negation should stay in to protect your Violent Outburst from Consign to Memory.