The phrase "cast a spell on" typically implies a sense of enchantment, captivation, or enchantment, but there are a variety of antonyms that might be employed in its stead. For instance, one could say that they have "broken the spell," indicating that they have dispelled or shattered the sense of enthrallment. Alternatively, one could say that they have "resisted the spell," indicating that they have remained impervious to the temptation or charm. Additionally, one could say that they have "rejected the spell," indicating an active, conscious decision to turn away from the allurement. Other potential antonyms might include words and phrases such as "banish," "shun," "ignore," or "distract from.