Demonic Demands

As an additional cost to cast this spell, you may
choose creatures you control.
Put a -1/-1 counter on each of those creatures.
Put -2/-2 counters on X target creatures.
If you put -1/-1 counters on creatures you control,
Put additional -1/-1 counters on X target
creatures, where X is the number of creatures
you put -1/-1 counters on.