Izzet Cauldron relies heavily on Agatha's Soul Cauldron interacting with graveyards and Stormchaser's Talent's level 2 recursion of instants/sorceries, so Rest in Peace shuts down both the Cauldron plan and any graveyard recursion while exiling their yard outright. Authority of the Consuls makes Fear of Missing Out and the Otter tokens from Stormchaser's Talent enter tapped, while the lifegain helps race the damage from Vivi Ornitier's triggers and their burn. Field of Ruin and Demolition Field are colorless lands that do little to advance your plan here, so trim those for the more proactive hate pieces. Keep your full removal suite since Vivi Ornitier and Agatha's Soul Cauldron are both must-answer permanents.