Children of Korlis

Sacrifice this creature: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Betor, Ancestor's Voice

Flying, lifelink
At the beginning of your end step, put a number of +1/+1 counters on up to one other target creature you control equal to the amount of life you gained this turn. Return up to one target creature card with mana value less than or equal to the amount of life you lost this turn from your graveyard to the battlefield.

Lathiel, the Bounteous Dawn

Lifelink
At the beginning of each end step, if you gained life this turn, distribute up to that many +1/+1 counters among any number of other target creatures.

Beledros Witherbloom

Flying
At the beginning of each upkeep, create a 1/1 black and green Pest creature token with "When this token dies, you gain 1 life."
Pay 10 life: Untap all lands you control. Activate only once each turn.