Gilder Bairn + Druids' Repository + Presence of Gond

Gilder Bairn

Druids' Repository

Presence of Gond

How it works

1. Activate Presence of Gond by tapping Gilder Bairn, producing its effect.
2. Activate Gilder Bairn by paying 2G/U and untapping it, doubling each counter on Druids' Repository.
3. Activate Druids' Repository 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 Druids' Repository, you may instead double the counters on any other permanents.