shindra, protector of weak

whenever you bond with a creature,
you may exile the top card of your library
under the bonded creature.
when the bonded creature leaves the battlefield
put the exiled card into your hand.
{2}{p/w}: bond (when you bond with a creature, that creature attacks,
blocks and leaves simultaneously. the creature who activated the bond returns when it leaves.
you can only bond with one creature at a time.)