Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Cindervines

Whenever an opponent casts a noncreature spell, Cindervines deals 1 damage to that player.
{1}, Sacrifice Cindervines: Destroy target artifact or enchantment. Cindervines deals 2 damage to that permanent's controller.

Smoke

Players can't untap more than one creature during their untap steps.

Desolation

At the beginning of each end step, each player who tapped a land for mana this turn sacrifices a land of their choice. Desolation deals 2 damage to each player who sacrificed a Plains this way.

Manabarbs

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

Winter Orb

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

Ramunap Excavator

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

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.

Squandered Resources

Sacrifice a land: Add one mana of any type the sacrificed land could produce.

Kardur, Doomscourge

When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able.
Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.