If you would proliferate, proliferate twice instead.
, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal. ( can be paid with either or 2 life.)
Tekuthal turns every proliferate trigger into two, snowballing counters across the board to win through oversized creatures, planeswalker ultimates, infinite combos, or poison. You spend the early game ramping and deploying proliferate engines, then chain triggers to overwhelm everyone with explosive counter growth.
Doubles every proliferate, making counter payoffs scale absurdly fast
Cheap 4-mana flier with built-in indestructibility for self-protection
Enables compact infect/poison and -1/-1 counter combo kills
Mono-blue gives access to the best card draw, counterspells, and tutors
Heavily reliant on the commander; removing Tekuthal halves your engine
Many proliferate payoffs are slow without the doubler online
Mono-blue lacks efficient creature removal and life gain
Can fold to board wipes before the indestructible counter is set up
With Mikaeus or counter doubling, removing/proliferating damage counters sets up infinite damage loops.
Add more proliferate engines (Inexorable Tide, Evolution Sage, Flux Channeler) and free repeatable sources so Tekuthal's doubling triggers constantly. Tighten the mana with fast rocks (Sol Ring, Mana Crypt) and protection (Swiftfoot Boots, counterspells) to keep the commander alive. For a true combo finish, include compact lines like Triskelion plus counter manipulation or infect tutors to win out of nowhere.