Gilder Bairn + Lost Jitte + Splinter Twin

Gilder Bairn

Lost Jitte

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 Lost Jitte.
3. Activate Lost Jitte three times by removing three charge counters from it, untapping three lands.
4. Activate those lands by tapping them, adding 2G/U.
5. Repeat from step 2.
6. Once you have infinite counters on Lost Jitte, you may instead double the counters on any other permanents.