Gilder Bairn + Citanul Hierophants + Iceberg

Gilder Bairn

Citanul Hierophants

Iceberg

How it works

1. Activate Citanul Hierophants by tapping Gilder Bairn, adding one mana.
2. Activate Gilder Bairn by paying 2G/U and untapping it, doubling each counter on Iceberg.
3. Activate Iceberg as many times as necessary by removing counters from it, adding at least two mana.
4. Repeat from step 2.
5. Once you have infinite counters on Iceberg, you may instead double the counters on any other permanents.