Blood Moon

Well of Life

At the beginning of your end step, if you control no untapped lands, you gain 2 life.

Mountain

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Chimeric Idol

{0}: Tap all lands you control. Chimeric Idol becomes a 3/3 Turtle artifact creature until end of turn.

Scoria Cat

Scoria Cat gets +3/+3 as long as you control no untapped lands.

Veteran Brawlers

Veteran Brawlers can't attack if defending player controls an untapped land.
Veteran Brawlers can't block if you control an untapped land.

Latulla, Keldon Overseer

{X}{R}, {T}, Discard two cards: Latulla, Keldon Overseer deals X damage to any target.

Keldon Berserker

Whenever Keldon Berserker attacks, if you control no untapped lands, it gets +3/+0 until end of turn.

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Branded Brawlers

Branded Brawlers can't attack if defending player controls an untapped land.
Branded Brawlers can't block if you control an untapped land.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Well of Discovery

At the beginning of your end step, if you control no untapped lands, draw a card.

Shiv's Embrace

Enchant creature
Enchanted creature gets +2/+2 and has flying.
{R}: Enchanted creature gets +1/+0 until end of turn.