Gilder Bairn + Crystalline Crawler + Cryptolith Rite

Gilder Bairn

Crystalline Crawler

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 Crystalline Crawler.
3. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding 2.
4. Repeat.
5. Once you have infinite +1/+1 counters on Crystalline Crawler, you may instead double the counters on any other permanent(s).

This loop relies on Gilder Bairn's ability to exponentially multiply the counters on Crystalline Crawler, turning every doubling cycle into a net gain of resources. Thanks to Cryptolith Rite granting every creature the ability to tap for any color of mana, you can easily generate the untap cost required to keep Gilder Bairn going. As Crystalline Crawler accumulates infinite +1/+1 counters through this process, you can strip them away for infinite mana of any color or simply use Gilder Bairn to overflow any other permanent you control with limitless counters.