Codie, Vociferous Codex, Umbral Mantle, and Training Grounds

Prerequisites

• Codie, Vociferous Codex on the battlefield
• Umbral Mantle on the battlefield
• Training Grounds on the battlefield
• Codie does not have summoning sickness
• Umbral Mantle attached to Codie
• available

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 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

Results

• Cast all instants and sorceries in your library with mana value less than spells you cast
• Infinite colored mana
• Infinitely large Codie until end of turn