Plains

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.

Speaker of the Heavens

Vigilance, lifelink (Attacking doesn't cause this creature to tap. Damage dealt by this creature also causes you to gain that much life.)
{T}: Create a 4/4 white Angel creature token with flying. Activate only if you have at least 7 life more than your starting life total and only as a sorcery.

Anointed Chorister

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
{4}{W}: Anointed Chorister gets +3/+3 until end of turn.

Faith's Fetters

Enchant permanent
When Faith's Fetters enters, you gain 4 life.
Enchanted permanent can't attack or block, and its activated abilities can't be activated unless they're mana abilities.

Basri's Acolyte

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Basri's Acolyte enters, put a +1/+1 counter on each of up to two other target creatures you control.

Revitalize

Take Heart

Target creature gets +2/+2 until end of turn. You gain 1 life for each attacking creature you control.

Mesa Unicorn

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Light of Promise

Enchant creature
Enchanted creature has "Whenever you gain life, put that many +1/+1 counters on this creature."

Bulwark Giant

When Bulwark Giant enters, you gain 5 life.

Swift Response

Griffin Aerie

At the beginning of your end step, if you gained 3 or more life this turn, create a 2/2 white Griffin creature token with flying.

Thriving Heath

Thriving Heath enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.