Swift Response

Cradle of Vitality

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

Path of Bravery

As long as your life total is greater than or equal to your starting life total, creatures you control get +1/+1.
Whenever one or more creatures you control attack, you gain life equal to the number of attacking creatures.

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.

Angel of Mercy

Flying
When Angel of Mercy enters, you gain 3 life.

Stone Haven Pilgrim

Whenever Stone Haven Pilgrim attacks, if you control an artifact or enchantment, Stone Haven Pilgrim gets +1/+1 and gains lifelink until end of turn.

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.

Revitalize

Bulwark Giant

When Bulwark Giant enters, you gain 5 life.

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.

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.

Plains

Brightmare

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

Alabaster Mage

{1}{W}: Target creature you control gains lifelink until end of turn. (Damage dealt by the creature also causes its controller to gain that much life.)