Rite of Balance

Biorhythm:
•{t}, {1}{g}, sacrifice a creature: Search your library
for a creature card with converted mana cost equal
to 1 plus the sacrificed creature's converted mana
cost, put that card onto the battlefield, then
shuffle your library. Activate this ability only any
time you could cast a sorcery.
•{t}, {1}{b}, sacrifice a creature: Return target
creature card from your graveyard to the
battlefield.
Life necessitates death