Sidisi, Undead Vizier, Helm of the Host, and Nexus of Fate

Prerequisites

• Sidisi, Undead Vizier on the battlefield
• Helm of the Host on the battlefield
• Nexus of Fate in the library
• Helm of the Host attached to Sidisi
• each turn available

Steps

1. At the beginning of combat on your turn, Helm of the Host triggers, creating a non-legendary copy of Sidisi with haste
2. The non-legendary Sidisi enters the battlefield, triggering its exploit ability, sacrificing itself
3. Sidisi's second ability triggers, allowing you to search your library for Nexus of Fate, put it into your hand, and shuffle your library
4. Cast Nexus of Fate by paying , causing you to take an extra turn after this one and shuffle it into your library
5. Repeat

Results

• Infinite turns