Codie, Vociferous Codex + Voltaic Construct + Training Grounds

Codie, Vociferous Codex

Voltaic Construct

Training Grounds

How it works

1. Activate Codie by paying 2 and tapping it, adding .
2. Activate Voltaic Construct by paying 1, 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 ingenious loop turns Codie, Vociferous Codex into an infinite mana engine by leaning on the cost-reduction power of Training Grounds to make Voltaic Construct's untap ability cheap enough to sustain. Each time you cycle through this process, you generate an abundance of colored mana while stacking up a mountain of delayed Codie triggers. Once you're ready to cash in, those triggers let you rip through your library and cast every single instant or sorcery with a lesser mana value entirely for free!