Veiled Apparition {1}{U}
Enchantment
When an opponent casts a spell, if this permanent is an enchantment, it becomes a 3/3 Illusion creature with flying and "At the beginning of your upkeep, sacrifice this creature unless you pay {1}{U}."
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Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.