Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent you controlled left the battlefield this turn.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Blossoming Calm

You gain hexproof until your next turn. You gain 2 life.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Wildgrowth Walker

Whenever a creature you control explores, put a +1/+1 counter on Wildgrowth Walker and you gain 3 life.

Razorverge Thicket

Razorverge Thicket enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Forest

Swamp

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Exquisite Blood

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Zuran Orb

Amalia Benavides Aguirre

Ward—Pay 3 life.
Whenever you gain life, Amalia Benavides Aguirre explores. Then destroy all other creatures if its power is exactly 20. (To have this creature explore, reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Horizon Canopy

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Horizon Canopy: Draw a card.

Case of the Uneaten Feast

Whenever a creature you control enters, you gain 1 life.
To solve — You've gained 5 or more life this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Sacrifice this Case: Creature cards in your graveyard gain "You may cast this card from your graveyard" until end of turn.

Plains

Haywire Mite

When Haywire Mite dies, you gain 2 life.
{G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

Cenote Scout

When Cenote Scout enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

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.

Elas il-Kor, Sadistic Pilgrim

Deathtouch
Whenever another creature you control enters, you gain 1 life.
Whenever another creature you control dies, each opponent loses 1 life.