Requires

Isochron Scepter must be on the battlefield. Energy Arc must be in exile (exiled by Isochron Scepter). Karn, Silver Golem must be on the battlefield. You control creatures that can tap to produce at least . Mana needed:

Steps

1. Activate Karn by paying , causing Isochron Scepter to become an artifact creature until end of turn.
2. Activate creatures you control by tapping those, adding .
3. Activate Isochron Scepter by paying and tapping it, casting a copy of Energy Arc without paying its mana cost, untapping all creatures.
4. Repeat from step 2.

Results