Gilder Bairn + Cryptic Trilobite + Cryptolith Rite

Gilder Bairn

Cryptic Trilobite

Cryptolith Rite

How it works

1. Activate Gilder Bairn by tapping it, adding G/U.
2. Activate Gilder Bairn by paying 2G/U and untapping it, doubling each counter on Cryptic Trilobite.
3. Activate Cryptic Trilobite's first ability by removing a +1/+1 counter from it, adding CC that can only be spent to activate abilities.
4. Repeat.
5. Once you have infinite +1/+1 counters on Cryptic Trilobite, you may instead double the counters on any other permanent(s).

This engine thrives by turning Cryptic Trilobite into an explosive mana battery, feeding its own growth through Gilder Bairn. With Cryptolith Rite granting your creatures the ability to tap for mana, you can pay the activation costs needed to untap Gilder Bairn and repeatedly double the +1/+1 counters resting on Cryptic Trilobite. Each doubling cycle leaves you with exponentially more counters than you started with, which translates to a massive surplus of colorless mana from Cryptic Trilobite's own ability—mana that conveniently fuels the very abilities keeping the loop going. Once you've achieved infinite +1/+1 counters and infinite ability-only mana, Gilder Bairn is free to double every other counter on your battlefield at will.