Heartstone [Stronghold] Time Spiral Timeshifted {T}: Add one mana of

{T}: Add one mana of any color

{T}: Destroy target black permanent

If you don't

Set: Kaladesh Prerelease Promos Type: Enchantment Rarity: Mythic Cost: {3}{U}{U} Whenever you cast an instant or sorcery spell

Set: Ravnica: City of Guilds Type: Instant Rarity: Common Cost: {1}{U}{B} Counter target spell unless its controller discards their hand

Heartstone [Stronghold] Time Spiral Timeshifted {T}: Add one mana ofSet: Stronghold Type: Artifact Rarity: Uncommon Cost: {3} Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana. "Finding a true heartstone is even harder than finding a true heart." Hanna