Quandrix Command + Crystalline Crawler + Kami of Whispered Hopes + Dualcaster Mage

Quandrix Command

Crystalline Crawler

Kami of Whispered Hopes

Dualcaster Mage

How it works

1. Cast Quandrix Command by paying its mana cost, choosing its first and third modes.
2. Holding priority, cast Dualcaster Mage by paying its mana cost.
3. When Dualcaster Mage enters, it triggers, copying Quandrix Command, with the copy's first mode targeting Dualcaster Mage and the copy's third mode targeting Crystalline Crawler.
4. Resolve the copy of Quandrix Command, returning Dualcaster Mage from the battlefield to your hand and putting three +1/+1 counters on Crystalline Crawler due to Kami of Whispered Hopes.
5. Holding priority, activate Crystalline Crawler three times by removing three +1/+1 counters from it, adding 1.
6. Repeat from step 2.

This clever loop puts Quandrix Command and Dualcaster Mage into a perpetual motion machine by leveraging the replacement effect of Kami of Whispered Hopes. When Dualcaster Mage enters to copy Quandrix Command, the spell bounces the Mage back to your hand while adding extra +1/+1 counters to Crystalline Crawler thanks to the Kami's amplification. You can then cash in those counters for the mana needed to recast Dualcaster Mage, generating an endless cascade of enters-the-battlefield triggers and storm count.