Riveteers Overlook

When Riveteers Overlook enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Witherbloom Campus

Witherbloom Campus enters tapped.
{T}: Add {B} or {G}.
{4}, {T}: Scry 1.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Tend the Pests

As an additional cost to cast this spell, sacrifice a creature.
Create X 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life," where X is the sacrificed creature's power.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Beledros Witherbloom

Flying
At the beginning of each upkeep, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."
Pay 10 life: Untap all lands you control. Activate only once each turn.

Cabaretti Courtyard

When Cabaretti Courtyard enters, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Prosperous Innkeeper

When Prosperous Innkeeper enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever another creature you control enters, you gain 1 life.

Brokers Hideout

When Brokers Hideout enters, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

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.)

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Dina, Soul Steeper

Whenever you gain life, each opponent loses 1 life.
{1}, Sacrifice another creature: Dina, Soul Steeper gets +X/+0 until end of turn, where X is the sacrificed creature's power.

Sedgemoor Witch

Menace
Ward—Pay 3 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 3 life.)
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Mortality Spear

This spell costs {2} less to cast if you gained life this turn.
Destroy target nonland permanent.

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Starscape Cleric

Offspring {2}{B} (You may pay an additional {2}{B} as you cast this spell. If you do, when this creature enters, create a 1/1 token copy of it.)
Flying
This creature can't block.
Whenever you gain life, each opponent loses 1 life.

Veinwitch Coven

Menace
Whenever you gain life, you may pay {B}. If you do, return target creature card from your graveyard to your hand.

Disciple of the Vault

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.