Crypt Ghast [Gatecrash]Set: Gatecrash Type: Creature Spirit Rarity: Rare Cost: {3}{B} Extort (Whenever you cast a spell, you may pay {W B}. If you do, each opponent loses 1 life and you gain that much life.) Whenever you tap a Swamp for mana, add an additional {B}.

If the player chooses others

Set: Commander 2017 Type: Creature — Dragon Rarity: Mythic Cost: {6}{R}{R} Flying

Enchanted land has "At the beginning of your upkeep

Set: Limited Edition Alpha Type: Enchantment Rarity: Uncommon Cost: {2}{W}{W} At the beginning of your upkeep

{T}: Double the amount of each type of unspent mana you have

The bigger they are

Whenever Goring Ceratops attacks

Put that card in your hand and exile all other cards revealed this way

When Necromancy enters the battlefield

Set: The Dark Type: Artifact Rarity: Uncommon Cost: {0} {T}

the player can activate mana abilities only if they're from lands that player controls and only if mana they produce is spent to activate other mana abilities of lands the player controls and/or to play that card

{T}: Target Assembly-Worker creature gets +1/+1 until end of turn