Incomplete Resurrection

At the beginning of your end step, you may pay
X life. If you do, return target creature card with
mana value X from your graveyard to the
battlefield tapped, then put a -1/-1 counter on it.
It is a Zombie in addition to its other types.
Half the army might collapse before the battle even
begins, but even then the enemy will be outnumbered
ten to one.