Isochron Scepter + Vitalize + Karn, the Great Creator

Isochron Scepter

Vitalize

Karn, the Great Creator

How it works

1. Activate Karn's first loyalty ability by adding a loyalty counter on it, causing Isochron Scepter to become an artifact creature until end of turn.
2. Activate creatures you control by tapping those, adding at least 3.
3. Activate Isochron Scepter by paying 2 and tapping it, casting a copy of Vitalize without paying its mana cost, untapping all creatures.
4. Repeat from step 2.

This loop relies on Isochron Scepter imprinted with Vitalize to continually untap your creatures, but since the Scepter itself needs to be tapped to activate its copy ability, it can't traditionally untap itself this way. Karn, the Great Creator solves this by using his +1 ability to turn Isochron Scepter into an artifact creature, allowing it to be tapped and untaped right along with the rest of your mana-producing creatures. Once the Scepter is animated, you simply tap it and pay {2} to cast Vitalize for free, untapping the Scepter and your mana creatures to repeat the process. This generates infinite creature-based mana and an infinite storm count, seamlessly weaving all three cards together into a single, self-sustaining engine.