Horobi, Death's Wail, Shadow Alley Denizen, and Overseer of the Damned

Prerequisites

• Horobi, Death's Wail on the battlefield
• Shadow Alley Denizen on the battlefield
• Overseer of the Damned on the battlefield
• You have a way to put a black creature onto the battlefield under your control

Steps

1. Put a black creature onto the battlefield under your control
2. Shadow Alley Denizen triggers, targeting any nontoken creature an opponent controls
3. Horobi triggers, destroying the targeted creature
4. When the creature dies, Overseer of the Damned's second ability triggers, creating a tapped 2/2 Zombie creature token
5. Repeat from step 2

Results

• Destroy any number of nontoken creatures opponents control whenever a black creature enters the battlefield under your control
• Destroy any number of nontoken creatures whenever a creature dies