Time Sieve, Tamiyo's Journal, Academy Manufactor, and Helm of the Host

Prerequisites

• Time Sieve on the battlefield
• Tamiyo's Journal on the battlefield
• Academy Manufactor on the battlefield
• Helm of the Host on the battlefield
• Helm of the Host attached to Academy Manufactor
• You control at least five additional artifacts

Steps

1. At the beginning of your combat phase, Helm of the Host triggers, creating a token copy of Academy Manufactor with haste
2. Activate Time Sieve by tapping it and sacrificing five artifacts, causing you to take an extra turn after this one
3. Move to your next turn
4. At the beginning of your upkeep, Tamiyo's Journal triggers, creating three Food, three Clue, and three Treasure artifact tokens
5. Repeat from step 2

Results

• Infinite turns