Lullmage Mentor + Primal Vigor + Doubling Season + Elspeth, Storm Slayer

Lullmage Mentor

Primal Vigor

Doubling Season

Elspeth, Storm Slayer

How it works

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.

This dazzling engine turns Lullmage Mentor into an absolute fortress by leveraging a cascade of token-doubling effects. Whenever you tap down seven Merfolk to counter an opponent's spell, Lullmage Mentor’s own trigger would normally replace that spell with a single new Merfolk; however, the compounding replacement effects of Primal Vigor, Doubling Season, and Elspeth, Storm Slayer explode that single token into an astonishing eight new Merfolk at once. This leaves you with far more than enough fresh bodies to immediately pay the seven-tap cost again, locking down the stack entirely while flooding the board with an unstoppable army.