Mechboy

{r}{r}{r}{t}—Return target creature or artifact
from your graveyard to play. If it's an artifact, it
gains Ramshackle. If it's a creature, roll a D20—
•1-7— Sacrifice this creature at the beginning of
your next end step. You lose 5 life.
•8-14{line}Put two +1/+1 counters on this creature.
It gains Firststrike. You lose 3 life.
•15-20{line}Whenever this creature deals damage to
a player, exchange control of it and another target creature. You lose 2 life.