Requires

Dualcaster Mage must be on the battlefield. Echo Storm must be in hand. Mycosynth Lattice must be on the battlefield. Mana needed:

Steps

1. Cast Echo Storm by paying , targeting Dualcaster Mage.
2. Echo Storm triggers, creating a copy of itself, targeting Dualcaster Mage.
3. Resolve the copy of Echo Storm, creating a token copy of Dualcaster Mage.
4. When the Dualcaster Mage token enters the battlefield, it triggers, creating a copy of Echo Storm, targeting Dualcaster Mage.
5. Repeat from step 3.

Results