Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Shizuko, Caller of Autumn

At the beginning of each player's upkeep, that player adds {G}{G}{G}. Until end of turn, they don't lose this mana as steps and phases end.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Gruul Signet

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Sol Ring

Horizon Stone

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

Golgari Signet

Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

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}.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Manabarbs

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

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Arcane Signet

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

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.)

Kodama's Reach

Leyline of Abundance

If Leyline of Abundance 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.

Rakdos Signet

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.