Bolas's Citadel [War of the Spark Promos] Karn and it was his weakness

and it was his weakness that pushed him

creatures you control get +2/+2 and gain trample until end of turn

or land you control and target permanent an opponent controls that shares one of those types with it

Exile the top card of your library: Put X +1/+1 counters on Phyrexian Devourer

Bolas's Citadel [War of the Spark Promos] Karn and it was his weaknessSet: War of the Spark Promos Type: Legendary Artifact 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 converted mana cost rather than pay its mana cost. {T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.