Requires

Codie, Vociferous Codex must be on the battlefield. Umbral Mantle must be on the battlefield. Zirda, the Dawnwaker must be on the battlefield. Codie does not have summoning sickness. Umbral Mantle attached to Codie. Mana needed:

Steps

1. Activate Codie by paying and tapping it, adding .
2. Activate Codie by paying and untapping it, giving it +2/+2 until end of turn.
3. Repeat.
4. Once you have an arbitrarily large number of Codie triggers, you may cast any instant or sorcery by paying its mana cost, reduced by the added in step 1.
5. Codie triggers for each time you activated its ability.
6. Resolve the first trigger, causing you to exile cards from the top of your library until you exile an instant or sorcery spell with lesser mana value, and allowing you to cast that spell without paying its mana cost.
7. Repeat step 6 for each remaining trigger.
8. You may also repeat this combo for each instant and sorcery card in your hand as mana permits, and on subsequent turns.

Results