Spellbinding Soprano, Sprout Swarm, and Storm-Kiln Artist

Prerequisites

• Spellbinding Soprano in the graveyard
• Sprout Swarm in hand
• Storm-Kiln Artist on the battlefield
• You have at least three opponents
• You control an untapped green creature
• available

Steps

1. Activate Spellbinding Soprano's encore ability by paying and exiling it from your graveyard, creating a token copy of it with haste for each opponent you have
2. Declare each Spellbinding Soprano token as an attacker
3. Each Spellbinding Soprano token triggers, causing instant and sorcery spells you cast this turn to cost less to cast for each Spellbinding Soprano token
4. Cast Sprout Swarm with buyback by paying and tapping a green creature you control
5. Storm-Kiln Artist triggers, creating a Treasure token
6. Resolve Sprout Swarm, creating a 1/1 Saproling creature token and returning Sprout Swarm to your hand
7. Activate the Treasure by tapping and sacrificing it, adding
8. Repeat from step 4

Results

• Infinite ETB
• Infinite magecraft triggers
• Infinite storm count
• Infinite tapped creature tokens