Lullmage Mentor, Elspeth, Storm Slayer, Parallel Lives, and Primal Vigor

Prerequisites

• Lullmage Mentor on the battlefield
• Elspeth, Storm Slayer on the battlefield
• Parallel Lives on the battlefield
• Primal Vigor on the battlefield

Steps

1. Whenever an opponent casts a spell, activate Lullmage Mentor by tapping seven untapped Merfolk, countering that spell
2. Lullmage Mentor triggers, creating a total of eight 1/1 Merfolk creature tokens
3. Repeat

Results

• Near-infinite ETB
• Counter all spells opponents cast
• Near-infinite tapped creature tokens