Lullmage Mentor + Adrix and Nev, Twincasters + Anointed Procession + Mondrak, Glory Dominus

Lullmage Mentor

Adrix and Nev, Twincasters

Anointed Procession

Mondrak, Glory Dominus

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 loop turns a single counterspell into an absolute lockdown by leveraging exponential token multiplication to immediately refuel your mana-free countermagic. When you activate Lullmage Mentor to counter an opponent's spell, its own triggered ability attempts to create a single Merfolk token, but the replacement effects of Adrix and Nev, Twincasters, Anointed Procession, and Mondrak, Glory Dominus compound together to multiply that single token into eight fresh Merfolk at once. Since you only needed to tap seven Merfolk to pay for Lullmage Mentor's ability, you net extra bodies with every single iteration, leaving you with a rapidly growing army to continuously counter every spell your opponents attempt to cast.