Codie, Vociferous Codex + Necrotic Ooze + Horseshoe Crab

Codie, Vociferous Codex

Necrotic Ooze

Horseshoe Crab

How it works

1. Activate Necrotic Ooze using Codie's ability by paying 4 and tapping it, adding .
2. Activate Necrotic Ooze using Horseshoe Crab's ability by paying , untapping Necrotic Ooze.
3. Repeat as desired, skipping step 2 on the final iteration.
4. Cast any spell by paying its mana cost, reduced by the added in step 1.
5. Necrotic Ooze triggers for each time you activated Codie's 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 nonland card in your hand as mana permits, and on subsequent turns.