Higher-rarity cards tend to be splashier, more complex, or more powerful because Wizards uses rarity to help manage Limited formats and card complexity
If flipped, it wipes off every monster, then forces players to excavate cards until they get as many monsters as were shuffled in each Main Deck
Good spells to use are: archetype support cards, searchers like Reinforcement of the Army or Preparation of Rites, monster destruction like Raigeki or Dark Hole, monster protection like Forbidden Lance, spell/trap destruction like Mystical Space Typhoon, and deck thinners like Upstart Goblin and Pot of Duality
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That theres a whole category of Magic cards designed to turn a situation like that around, that couldve saved your life and delivered you to a well-earned victory