Emeria Shepherd, Felidar Guardian, and Phyrexian Altar

Prerequisites

• Emeria Shepherd on the battlefield
• Felidar Guardian in hand
• Phyrexian Altar on the battlefield
• You control Plains
• available

Steps

1. Cast Felidar Guardian by paying
2. Felidar Guardian enters the battlefield, blinking Plains
3. Emeria Shepherd triggers
4. Holding priority, activate Phyrexian Altar by sacrificing Felidar Guardian, adding one mana of any color
5. Resolve the Emeria Shepherd trigger, returning Felidar Guardian from your graveyard to the battlefield
6. Repeat from step 2

Results

• Infinite colored mana
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers