Lullmage Mentor + Mondrak, Glory Dominus + Doubling Season + Elspeth, Storm Slayer

Lullmage Mentor

Mondrak, Glory Dominus

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 clever lock relies on Lullmage Mentor to continuously counter your opponents' spells by tapping a swarm of seven Merfolk. Whenever that activated ability counters a spell, the Mentor triggers to generate a 1/1 Merfolk, but the presence of Mondrak, Glory Dominus, Doubling Season, and Elspeth, Storm Slayer radically multiplies that output through their cumulative replacement effects, turning a single token creation into a massive windfall of eight new Merfolk. With your army instantly replenished far beyond the seven needed for the cost, you can repeat the process indefinitely to completely shut down opposing spells while flooding the board.