Destroy each creature that enters the battlefield under an opponent's control, Destroy all creatures opponents control, Lock
Give Sengir deathtouch, if needed.
Activate Sengir using Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 1 damage to any creature an opponent controls, and killing it due to Sengir's deathtouch.
When the creature dies, Sengir's first ability triggers, putting two +1/+1 counters on it.
Repeat from step 2 as desired.
Component Cards
How It Works
Give Sengir deathtouch, if needed.
Activate Sengir using Walking Ballista's second ability by removing a +1/+1 counter from it, dealing 1 damage to any creature an opponent controls, and killing it due to Sengir's deathtouch.
When the creature dies, Sengir's first ability triggers, putting two +1/+1 counters on it.
Repeat from step 2 as desired.