Doppelgang + Echo Mage + Deceiver Exarch

Doppelgang

Echo Mage

Deceiver Exarch

How it works

1. Cast Doppelgang by paying 6, targeting Deceiver Exarch and a mana-producing permanent.
2. Holding priority, activate Echo Mage by paying and tapping it, copying Doppelgang, targeting Deceiver Exarch and a mana-producing permanent.
3. Resolve the copy of Doppelgang, creating two copies of Deceiver Exarch and the mana-producing permanent.
4. When the Deceiver Exarch tokens enter, they trigger, untapping Echo Mage and any other applicable permanent.
5. Holding priority, activate the two mana-producing permanent tokens by tapping them, adding at least .
6. Repeat from step 2.

This clever loop hinges on a fully leveled Echo Mage reaching level 4 or higher, granting it the devastating ability to copy instant and sorcery spells twice for a modest mana investment. By casting Doppelgang with a massive X value to target both a mana-producing permanent and a Deceiver Exarch, you set the stage for an explosive cascade of value. When Echo Mage copies that Doppelgang, the resulting token copies of Deceiver Exarch enter the battlefield and trigger to untap your mana sources and the Mage itself, while the new mana-producing permanent tokens fuel the next iteration. This engine completely breaks wide open, generating infinite creature tokens, permanent copies, and infinite mana to fuel whatever else your heart desires.