Gilder Bairn + Gemstone Array + Splinter Twin

Gilder Bairn

Gemstone Array

Splinter Twin

How it works

1. Activate Splinter Twin by tapping Gilder Bairn, producing its effect.
2. Activate Gilder Bairn by paying 2G/U and untapping it, doubling each counter on Gemstone Array.
3. Activate Gemstone Array as many times as necessary by removing counters from it, adding at least three mana.
4. Repeat from step 2.
5. Once you have infinite counters on Gemstone Array, you may instead double the counters on any other permanents.