Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

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.

Runic Armasaur

Whenever an opponent activates an ability of a creature or land that isn't a mana ability, you may draw a card.

Zhur-Taa Ancient

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}.

Heartwood Storyteller

Whenever a player casts a noncreature spell, each of that player's opponents may draw a card.

Arcane Encyclopedia

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

Manabarbs

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