Geryon, Simic Emissary

: Each creature with +1/+1 counters on them is a Mutant in addition to their other types.
+2: Put 2 +1/+1 counters on target non-Mutant creature.
-4: All creatures get -2/-2 until end of turn. Whenever a creature would die this turn, put a +1/+1 counter on each Mutant you control