Niadresh, High Biomage

+2: Pay 2 life: each opponent discards a card, each opponent loses one life, and you place two +1/+1 counters on target creature.
+4: Remove any number of +1/+1 counters from creatures you control: create a 1/1 legendary Experiment token with this many +1/+1 counters.
-12: Sacrifice an Experiment token: each opponent loses half their life, discards half their hand, and you gain 10 life.