Azorius Replenish is a combo deck that wins by filling the graveyard with enchantments via Attunement and Frantic Search, then casting Replenish to put Opalescence and Parallax Wave into play simultaneously, creating a board of large creatures with a lock. Your primary plan is to kill them before they can assemble the combo, as your aggressive red and green creatures backed by direct damage are faster than their setup. Hull Breach is a must-include as a two-for-one that can destroy both an Opalescence and a Parallax Wave for just two mana, which is backbreaking if they do manage to resolve Replenish. The extra Naturalize copies provide additional ways to answer key enchantments like Seal of Cleansing, Opalescence, or Parallax Wave mid-combo. Seal of Fire comes out because it is the weakest burn spell against a deck with few small creatures, and the mainboard Naturalize copies are redundant given you are already bringing in more from the sideboard.