Gyruda, Doom of Depths, Mortuary, and Phyrexian Altar

Prerequisites

• Gyruda, Doom of Depths in hand or in the command zone
• Mortuary on the battlefield
• Phyrexian Altar on the battlefield
• plus enough mana to pay for commander tax, if applicable available

Steps

1. Cast Gyruda by paying and commander tax, if applicable
2. Gyruda enters the battlefield, triggering its ability
3. Holding priority, activate Phyrexian Altar by sacrificing Gyruda, adding one mana of any color
4. Gyruda dies, triggering Mortuary, putting Gyruda on top of your library from your graveyard
5. Resolve the Gyruda ability from step 2, causing each player to mill four cards and you to return Gyruda from your graveyard to the battlefield
6. Repeat from step 2

Results

• Infinite colored mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill