Archelos, Lagoon Mystic, Gretchen Titchwillow, Training Grounds, and Simic Growth Chamber

Prerequisites

• Archelos, Lagoon Mystic on the battlefield
• Gretchen Titchwillow on the battlefield
• Training Grounds on the battlefield
• Simic Growth Chamber in hand
• Archelos is untapped

Steps

1. Play Simic Growth Chamber
2. Simic Growth Chamber enters the battlefield untapped due to Archelos, triggering itself
3. Holding priority, activate Simic Growth Chamber by tapping it, adding
4. Resolve the Simic Growth Chamber trigger from step 2, returning itself to your hand from the battlefield
5. Activate Gretchen Titchwillow by paying , causing you to draw a card and put Simic Growth Chamber from your hand onto the battlefield
6. Repeat from step 2

Results

• Infinite card draw
• Infinite draw triggers
• Near-infinite landfall triggers