Metanoia

Whenever a creature is put into the graveyard
from the battlefield, you may sacrifice Metanoia.
If you do, return that card to the battlefield
under your control. If a creature returned to the
battlefield in this manner is owned by you, gain
life equal to its toughness. Otherwise its owner
loses life equal to its power.
"In conversion you are not attached primarily to an
order...you are attached primarily to a Person, and secondarily to other things." - E. Stanley Jones