wall of life

Defender (This creature can't attack.) Pay 1 life: This creature gets +1/+1 until end of turn.

If you would gain life, you gain twice that much life instead.

Whenever you gain life, you may pay . If you do, put a +1/+1 counter on target creature for each 1 life you gained.

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