Kinnan, Bonder Prodigy, Machine God's Effigy, and Horseshoe Crab

Prerequisites

• Kinnan, Bonder Prodigy on the battlefield
• Machine God's Effigy in hand
• Horseshoe Crab on the battlefield
• available

Steps

1. Cast Machine God's Effigy by paying , choosing to have it enter the battlefield as a copy of Horseshoe Crab that is an artifact
2. Activate Machine God's Effigy by tapping it, adding
3. Kinnan triggers, adding
4. Activate Machine God's Effigy by paying , untapping it
5. Repeat from step 2

Results

• Infinite blue mana