Codie, Vociferous Codex + High Alert + Opalescence + Biomancer's Familiar

Codie, Vociferous Codex

High Alert

Opalescence

Biomancer's Familiar

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 fascinating loop turns Codie, Vociferous Codex into an engine for infinite mana and cascading spellcasting by leveraging Opalescence to make Codie and High Alert into creatures. Once they are creatures, Biomancer's Familiar steps in to slash the activation cost of High Alert's untap ability down to just {W}{U}, allowing you to endlessly untap Codie and generate infinite mana of all five colors. Each activation of Codie's ability stacks up a delayed trigger that lets you rip through your library and cast instant or sorcery spells completely for free.