The Slayer's Testament

I - You may cast spells from your graveyard that
targets creatures you control while this Saga is on
the battlefield.
II - Target creature you control may fight any
number of target creatures. Put a +1/+1 counter
on it for each creature destroyed this way.
III - Destroy target creature and target permanent.
If you do, exile creature you control targeted by II
at the beginning of the next end step.