Codie, Vociferous Codex + High Alert + Opalescence + Training Grounds

Codie, Vociferous Codex

High Alert

Opalescence

Training Grounds

How it works

1. Activate Codie by paying 2 and tapping it, adding .
2. Activate High Alert by paying , untapping Codie.
3. Repeat.
4. Once you have an arbitrarily large number of Codie triggers, you may cast any instant or sorcery spell by paying its mana cost.
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/or sorcery card in your hand, and on subsequent turns.

This intricate setup transforms Codie, Vociferous Codex into an engine of boundless mana by leveraging Opalescence, which turns Codie into a creature so it can be repeatedly untap-targeted. High Alert provides the crucial untap ability to refresh Codie, while Training Grounds radically reduces that ability's cost, making the loop possible with the five mana produced by Codie itself. As you loop these activations, Codie's cascading trigger builds up exponentially, allowing you to eventually rifle through your library and cast every instant and sorcery without paying their mana costs.