Lullmage Mentor + Adrix and Nev, Twincasters + Mondrak, Glory Dominus + Exalted Sunborn

Lullmage Mentor

Adrix and Nev, Twincasters

Mondrak, Glory Dominus

Exalted Sunborn

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 lock works by turning a single counterspell into an exponential token-generating engine that feeds right back into itself. Whenever an opponent casts a spell, you activate Lullmage Mentor's ability to counter it by tapping seven untapped Merfolk. That successful counter triggers Lullmage Mentor's first ability to create a token, but because replacement effects stack from Adrix and Nev, Twincasters, Mondrak, Glory Dominus, and Exalted Sunborn all multiplying that single token creation by two each, that one trigger instead floods the board with eight brand-new Merfolk. With those fresh bodies ready to tap, you can repeat the process to counter every single spell your opponents try to cast while continuously growing your army.