Soul's Attendant

Whenever another creature enters the battlefield, you may gain 1 life.

Angel of Indemnity

Flying, lifelink
When Angel of Indemnity enters the battlefield, return target permanent card with mana value 4 or less from your graveyard to the battlefield.
Encore {6}{W}{W} ({6}{W}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 life.

Blood Burglar

As long as it's your turn, Blood Burglar has lifelink. (Damage dealt by this creature also causes you to gain that much life.)

Liesa, Forgotten Archangel

Flying, lifelink
Whenever another nontoken creature you control dies, return that card to its owner's hand at the beginning of the next end step.
If a creature an opponent controls would die, exile it instead.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature.

Kambal, Profiteering Mayor

Whenever one or more tokens enter the battlefield under your opponents' control, for each of them, create a tapped token that's a copy of it. This ability triggers only once each turn.
Whenever one or more tokens enter the battlefield under your control, each opponent loses 1 life and you gain 1 life.

Liesa, Shroud of Dusk

Rather than pay {2} for each previous time you've cast this spell from the command zone this game, pay 2 life that many times.
Flying, lifelink
Whenever a player casts a spell, they lose 2 life.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, Serra Ascendant gets +5/+5 and has flying.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

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.