Krark, the Thumbless, and Spark Double

Prerequisites

• Krark, the Thumbless on the battlefield
• Spark Double on the battlefield

Steps

1. Cast the instant or sorcery that creates a copy of a creature by paying its mana cost, targeting Spark Double
2. When you cast that spell, Krark and any additional copies of Krark trigger
3. Resolve all Krark triggers, copying that spell for each flip you won, and returning the original to your hand as long as you lost at least one flip
4. Resolve each copy of that spell, creating a token copy of Krark each time
5. If that spell is back in your hand and you need additional mana, cast the Mana Ritual by paying its costs, then repeat from step 2
6. If that spell is back in your hand and you have enough mana, instead repeat from step 1
7. If you won every flip, instead resolve the card itself, creating one more Krark token and putting the card into your graveyard
8. If you manage to pass a critical threshold of Krark copies before the copying spell ends up in your graveyard, this combo is overwhelmingly likely to be an infinite loop from that point on
9. See the widget below for failure chances
10. Once you have infinite mana and infinite copies of Krark, you can repeat this loop with any instant or sorcery you can cast

Results

• Infinite copies of creatures you control
• Infinite copies of instant or sorcery spells you cast
• Infinite magecraft triggers
• Infinite storm count