Urza's Incubator + Lutri, the Spellchaser + Airbender's Reversal

Urza's Incubator

Lutri, the Spellchaser

Airbender's Reversal

How it works

1. Cast Airbender's Reversal by paying its mana cost, targeting any applicable target(s).
2. Holding priority, cast Lutri by paying its mana cost reduced by Urza's Incubator.
3. When Lutri enters, it triggers, copying Airbender's Reversal targeting Lutri.
4. Resolve Airbender's Reversal, airbending Lutri.
5. Holding priority, cast Lutri from exile by paying 0 due to Urza's Incubator.
6. Repeat from step 3.

This clever loop turns Urza's Incubator—which is set to the Otter creature type to discount our spells—into a bridge for endless recursion by cheapening Lutri, the Spellchaser's casting costs. When you cast Lutri, its entry trigger copies Airbender's Reversal, targeting Lutri itself to exile it and set up its unique "airbend" alternate-cost casting. Because Urza's Incubator reduces Lutri's {2} exile cost down to nothing, you can replay the companion for free every single time Airbender's Reversal resolves. This generates an unstoppable cascade of enter-the-battlefield triggers, leaving-the-battlefield triggers, and storm count for formats like Commander and Legacy.