Overabundance

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and this enchantment deals 1 damage to the player.

Victory Chimes

Untap this artifact during each other player's untap step.
{T}: A player of your choice adds {C}.

Lavalanche

Lavalanche deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Collective Voyage

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles.

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath gets +1/+1 for each unspent green mana you have.

Magus of the Vineyard

At the beginning of each player's first main phase, that player adds {G}{G}.

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When this creature dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

Eladamri's Vineyard

Mana Flare

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

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on this enchantment.
At the beginning of your upkeep, if there are 100 or more tower counters on this enchantment, you win the game.

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Runic Armasaur

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

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}.

Belbe, Corrupted Observer

At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Manabarbs

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

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Staff of Domination

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

Leyline of Abundance

If this card is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.