Knowledge Exploitation [Morningtide] 232 but its original ATK becomes

but its original ATK becomes 0

Set: Eighth Edition Type: Land Rarity: Rare Whenever City of Brass becomes tapped

Set: EX: Sandstorm Type: Colorless Rarity: Promo

Set: Eventide Type: Enchantment Rarity: Uncommon Cost: {1}{B} At the beginning of your upkeep

Set: Diamond & Pearl: Secret Wonders Type: Lightning Rarity: Rare Retreat cost: Colorless

Knowledge Exploitation [Morningtide] 232 but its original ATK becomesSet: Morningtide Type: Tribal Sorcery Rogue Rarity: Rare Cost: {5}{U}{U} Prowl {3}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.) Search target opponent's library for an instant or sorcery card. You may cast that card without paying its mana cost. Then that player shuffles.