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.

Evra, Halcyon Witness

Lifelink
{4}: Exchange your life total with Evra's power.

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

Defender, flying
At the beginning of your end step, you may gain life equal to the power of target creature you control.