Interrogation Robot [Unknown Event] Pest Sacrifice an artifact: Search your

Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value

You don't search for a Knight when this enters the battlefield

Set: March of the Machine: The Aftermath Type: Legendary Creature — Human Shaman Rarity: Mythic Cost: {1}{U}{R} Dragon spells you cast cost 1 less to cast

Set: Zendikar Rising Prerelease Promos Type: Creature — Dragon Rarity: Mythic Cost: {2}{R}{R} Flying

Set: Mystery Booster Type: Enchantment Rarity: Rare Cost: {3}{B}{B} Flash

Interrogation Robot [Unknown Event] Pest Sacrifice an artifact: Search yourSet: Unknown Event Type: Artifact Creature Construct Rarity: Uncommon Cost: {3} {T}, Discard a card: Choose a card name that hasn't been chosen among Who, What, When, Where, and Why. Create a copy of the card with the chosen name. You may cast the copy. (You still pay its costs. Who What When Where Why is a split card from Unhinged.)