Gilder Bairn + Pentad Prism + Enduring Vitality

Gilder Bairn

Pentad Prism

Enduring Vitality

How it works

1. Activate Enduring Vitality by tapping Gilder Bairn, adding one mana.
2. Activate Gilder Bairn by paying 2G/U and untapping it, doubling each counter on Pentad Prism.
3. Activate Pentad Prism 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 Pentad Prism, you may instead double the counters on any other permanents.