Codie, Vociferous Codex + Umbral Mantle + Training Grounds

Codie, Vociferous Codex

Umbral Mantle

Training Grounds

How it works

1. Activate Codie by paying 2 and tapping it, adding .
2. Activate Codie by paying 1 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 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 engine of infinite mana and cascading spells by leveraging a clever cost reduction. While Training Grounds lowers Codie's untap cost to just one generic mana, equipping Umbral Mantle allows you to pump and untap the Codex repeatedly, generating unlimited five-color mana along the way. Each activation also puts a delayed cascade trigger on the stack, meaning you can eventually sift through your entire library to cast every instant or sorcery you desire without paying their mana costs.