Serene Steward

Whenever you gain life, you may pay {W}. If you do, put a +1/+1 counter on target creature.

Swamp

Stone Haven Medic

Shadow Glider

Hagra Sharpshooter

{4}{B}: Target creature gets -1/-1 until end of turn.

Demon's Grasp

Target creature gets -5/-5 until end of turn.

Mortuary Mire

This land enters tapped.
When this land enters, you may put target creature card from your graveyard on top of your library.
{T}: Add {B}.

Courier Griffin

Flying
When this creature enters, you gain 2 life.

Plains

Zulaport Cutthroat

Whenever this creature or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Felidar Sovereign

Vigilance (Attacking doesn't cause this creature to tap.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your upkeep, if you have 40 or more life, you win the game.

Gideon's Reproach

Gideon's Reproach deals 4 damage to target attacking or blocking creature.

Tandem Tactics

Up to two target creatures each get +1/+2 until end of turn. You gain 2 life.

Evolving Wilds

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

Nirkana Assassin

Whenever you gain life, this creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Kitesail Scout

Kalastria Nightwatch

Whenever you gain life, this creature gains flying until end of turn.

Defiant Bloodlord

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

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Dutiful Return

Return up to two target creature cards from your graveyard to your hand.

Roil's Retribution

Roil's Retribution deals 5 damage divided as you choose among any number of target attacking or blocking creatures.

Blighted Steppe

{T}: Add {C}.
{3}{W}, {T}, Sacrifice this land: You gain 2 life for each creature you control.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on this creature.

Malakir Familiar

Flying, deathtouch
Whenever you gain life, this creature gets +1/+1 until end of turn.