Bogbrew Witch, Festering Newt, Mortuary, Ashnod's Altar, and Thornbite Staff

Prerequisites

• Bogbrew Witch on the battlefield
• Festering Newt in the library
• Mortuary on the battlefield
• Ashnod's Altar on the battlefield
• Thornbite Staff on the battlefield
• Bogbrew Witch does not have summoning sickness
• Thornbite Staff attached to Bogbrew Witch
• available

Steps

1. Activate Bogbrew Witch by paying and tapping it, searching your library for Festering Newt and putting it onto the battlefield
2. Activate Ashnod's Altar by sacrificing Festering Newt, adding
3. When Festering Newt dies, it, Bogbrew Witch and Mortuary trigger
4. Resolve the Festering Newt trigger, giving any creature an opponent controls -4/-4 until end of turn
5. Resolve the Mortuary trigger, putting Festering Newt on top of your library from your graveyard
6. Resolve the Bogbrew Witch trigger, untapping it
7. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Reduce any number of opposing creatures' toughness to zero