Leviathan [The Dark] Tribal Enchantment lands tapped for mana produce

lands tapped for mana produce mana of the chosen color instead of any other color

(Then put Timetwister into its owner's graveyard

Set: Kaladesh Inventions Type: Artifact Rarity: Mythic Cost: {2} Each spell costs {3} more to cast except during its controller's turn

Set: Beta Edition Type: Sorcery Rarity: Uncommon Cost: {2}{G} Destroy target land

as you untap your permanents

Leviathan [The Dark] Tribal Enchantment lands tapped for mana produceSet: The Dark Type: Creature Leviathan Rarity: Rare Cost: {5}{U}{U}{U}{U} Trample Leviathan enters the battlefield tapped and doesn't untap during your untap step. At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap Leviathan. Leviathan can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)