Tariel, Reckoner of Souls, and Intruder Alarm

Prerequisites

• Tariel, Reckoner of Souls on the battlefield
• Intruder Alarm on the battlefield
• Tariel does not have summoning sickness

Steps

1. Activate Tariel by tapping it, putting a creature card from an opponent's graveyard onto the battlefield under your control
2. The creature enters the battlefield, triggering Intruder Alarm, untapping all creatures
3. Repeat

Results

• Put all creatures from each opponent's graveyard onto the battlefield under your control