Activate Codie by paying ({U} magic symbol) , untapping it.
Repeat.
Once you have an arbitrarily large number of Codie triggers, you may cast any instant or sorcery spell by paying its mana cost.
Codie triggers for each time you activated its ability.
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.
Repeat step 6 for each remaining trigger.
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.