Ajani's Pridemate

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

Authority of the Consuls

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

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Celestine, the Living Saint

Flying, lifelink
Healing Tears — At the beginning of your end step, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.

Hinterland Sanctifier

Whenever another creature you control enters, you gain 1 life.