Emptiness, Phyrexian Altar, and Dundoolin Weaver

Prerequisites

• Emptiness in hand
• Phyrexian Altar on the battlefield
• Dundoolin Weaver in the graveyard
• available

Steps

1. Cast Emptiness for its evoke cost by paying
2. When Emptiness enters, its first ability and evoke ability trigger
3. Holding priority, activate Phyrexian Altar by sacrificing Emptiness, adding
4. Resolve Emptiness's evoke trigger, failing to sacrifice it as it's no longer on the battlefield
5. Resolve Emptiness's first trigger, returning Dundoolin Weaver from your graveyard to the battlefield
6. When Dundoolin Weaver enters, it triggers, returning Emptiness from your graveyard to your hand
7. Activate Phyrexian Altar by sacrificing Dundoolin Weaver, adding
8. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite storm count