Mana Echoes + Symmetry Matrix + The Watcher in the Water

UR identity

Commander legal

The 3 combo pieces

• Mana Echoes
• Symmetry Matrix
• The Watcher in the Water

What must be in place

You have a way to draw a card during an opponent's turn.

How to execute it

1. Draw a card during an opponent's turn.
2. The Watcher's first ability riggers, creating a 1/1 Tentacle creature token.
3. When the Tentacle enters the battlefield, Symmetry Matrix and Mana Echoes trigger.
4. Resolve the Mana Echoes trigger, adding {C} for each Tentacle on the battlefield.
5. Resolve the Symmetry Matrix trigger, causing you to pay {1} to draw a card.
6. Repeat from step 2.

What the combo produces

• Infinite card draw
• Infinite draw triggers
• Near-infinite colorless mana
• Near-infinite creature sacrifice triggers
• Near-infinite creature tokens
• Near-infinite death triggers
• Near-infinite ETB
• Near-infinite LTB