Bolas's Citadel [War of the Spark] The Brothers' War Commander Set: March of the Machine:

Set: March of the Machine: The Aftermath Type: Legendary Creature — Demon Rarity: Mythic Cost: {2}{R}{G} Flying

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

then exile those cards

For as long as that card remains exiled

trample counter

Bolas's Citadel [War of the Spark] The Brothers' War Commander Set: March of the Machine:Set: War of the Spark Type: Legendary Artifact Rarity: Rare Cost: {3}{B}{B}{B} You may look at the top card of your library any time. You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost. {T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.