Enduring Tenacity

Whenever you gain life, target opponent loses that much life.
When Enduring Tenacity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Sun-Blessed Healer

Kicker {1}{W} (You may pay an additional {1}{W} as you cast this spell.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, if it was kicked, return target nonland permanent card with mana value 2 or less from your graveyard to the battlefield.

Minwu, White Mage

Vigilance, lifelink
Whenever you gain life, put a +1/+1 counter on each Cleric you control.

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Venerated Stormsinger

Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)
Whenever this creature or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Plains

Scoured Barrens

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {B}.

The Wind Crystal

White spells you cast cost {1} less to cast.
If you would gain life, you gain twice that much life instead.
{4}{W}{W}, {T}: Creatures you control gain flying and lifelink until end of turn.

Bleachbone Verge

{T}: Add {B}.
{T}: Add {W}. Activate only if you control a Plains or a Swamp.

Hallowed Priest

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

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Soulmender

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Aerith Gainsborough

Lifelink
Whenever you gain life, put a +1/+1 counter on Aerith Gainsborough.
When Aerith Gainsborough dies, put X +1/+1 counters on each legendary creature you control, where X is the number of +1/+1 counters on Aerith Gainsborough.