Twilight Shepherd, Phyrexian Altar, and Sneak Attack

Prerequisites

• Twilight Shepherd on the battlefield
• Phyrexian Altar on the battlefield
• Sneak Attack on the battlefield

Steps

1. Sacrifice Twilight Shepherd to Phyrexian Altar to add
2. Twilight Shepherd's persist triggers, returning it to the battlefield with a -1/-1 counter
3. Sacrifice Twilight Shepherd to Phyrexian Altar to add
4. Twilight Shepherd triggers, returning it from your graveyard to your hand
5. Pay to Sneak Attack to put Twilight Shepherd onto the battlefield from your hand
6. Repeat

Results

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