Sisters of Flesh and Spirit

Protection from non-Spirit creatures
Other Spirits you control have "Soulshift X,
where X is equal to this creatures converted mana
cost minus 1."
Whenever Sisters of Flesh and Spirit enters or
leaves the battlefield, choose one—
•Search your library for a Spirit creature card
and put it into your graveyard.
•Return target Spirit creature card from your graveyard to your hand.