You may choose not to untap Ashnod's Battle Gear during your untap step.

, : Target creature you control gets +2/-2 for as long as Ashnod's Battle Gear remains tapped.

Remove Bronze Tablet from your deck before playing if you're not playing for ante.

Bronze Tablet enters tapped.

, : Exile Bronze Tablet and target nontoken permanent an opponent owns. That player may pay 10 life. If they do, put Bronze Tablet into its owner's graveyard. Otherwise, that player owns Bronze Tablet and you own the other exiled card.

Tap target untapped creature you control. If you do, add an amount of equal to that creature's mana value.

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Trample

Leviathan enters 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.)

Blue creatures don't untap during their controllers' untap steps.

At the beginning of each player's upkeep, that player may choose any number of tapped blue creatures they control and pay for each creature chosen this way. If the player does, untap those creatures.

Nevinyrral's Disk enters tapped.

, : Destroy all artifacts, creatures, and enchantments.

Enchant land

Whenever enchanted land becomes tapped, Psychic Venom deals 2 damage to that land's controller.

: Destroy target tapped creature.

You may choose not to untap Tawnos's Weaponry during your untap step.

, : Target creature gets +1/+1 for as long as Tawnos's Weaponry remains tapped.

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.