Neketh, Chosen of Advena

0: Place -1/-1 counter on any creature permanents target opponent controls that do not have any, then Proliferate.
-3: create a 2/2 Changeling creature token with either flying or deathtouch then place a +1/+1 counter on all creatures you control.
-7: Take control of all creatures on the battlefield with at least 1 -1/-1 counter, then change all -1/-1 counters on all creatures to +1/+1.