Dina, Soul Steeper

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

Lisette, Dean of the Root

Whenever you gain life, you may pay {1}. If you do, put a +1/+1 counter on each creature you control and those creatures gain trample until end of turn.

Valentin, Dean of the Vein

Menace, lifelink
If a nontoken creature an opponent controls would die, exile it instead. When you do, you may pay {2}. If you do, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Valentin, Dean of the Vein // Lisette, Dean of the Root

Overgrown Arch

Defender
{T}: You gain 1 life.
{2}, Sacrifice this creature: Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Hunt for Specimens

Create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Blood Researcher

Menace (This creature can't be blocked except by two or more creatures.)
Whenever you gain life, put a +1/+1 counter on this creature.

Mortality Spear

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

Woe Strider

When this creature enters, create a 0/1 white Goat creature token.
Sacrifice another creature: Scry 1.
Escape—{3}{B}{B}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
This creature escapes with two +1/+1 counters on it.

Swamp

Pest Summoning

Create two 1/1 black and green Pest creature tokens with "When this token dies, you gain 1 life."

Bastion of Remembrance

When this enchantment 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.

Introduction to Prophecy

Eyetwitch

Flying
When this creature dies, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Necrotic Fumes

As an additional cost to cast this spell, exile a creature you control.
Exile target creature or planeswalker.

Forest

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 token dies, you gain 1 life."

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Daemogoth Woe-Eater

At the beginning of your upkeep, sacrifice a creature.
When you sacrifice this creature, each opponent discards a card, you draw a card, and you gain 2 life.

Daemogoth Titan

Whenever this creature attacks or blocks, sacrifice a creature.

Plumb the Forbidden

As an additional cost to cast this spell, you may sacrifice one or more creatures. When you do, copy this spell for each creature sacrificed this way.
You draw a card and you lose 1 life.

Callous Bloodmage

When this creature enters, choose one —
• Create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
• You draw a card and you lose 1 life.
• Exile target player's graveyard.

Containment Breach

Destroy target artifact or enchantment. If its mana value is 2 or less, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."

Witherbloom Campus

This land enters tapped.
{T}: Add {B} or {G}.
{4}, {T}: Scry 1.

Restorative Burst

Return up to two target creature, land, and/or planeswalker cards from your graveyard to your hand. Each player gains 4 life. Exile Restorative Burst.

Pestilent Cauldron

{T}, Discard a card: Create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
{1}, {T}: Each opponent mills cards equal to the amount of life you gained this turn.
{4}, {T}: Exile four target cards from a single graveyard. Draw a card.

Pestilent Cauldron // Restorative Burst

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 token dies, you gain 1 life," where X is the sacrificed creature's power.