Celestine, the Living Saint + Coretapper + Magistrate's Scepter

Celestine, the Living Saint
Coretapper
Magistrate's Scepter

Requires
All permanents on the battlefield. Celestine and Coretapper do not have summoning sickness. An opponent is unable to block and kill Celestine.
Steps
  1. Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter
  2. Activate Coretapper's second ability by sacrificing it, putting two charge counters on Magistrate's Scepter
  3. Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, causing you to take an extra turn after this one
  4. Deal combat damage using Celestine, causing you to gain three life
  5. At the beginning of your end step, Celestine triggers, returning Coretapper from your graveyard to the battlefield
  6. Repeat each turn
Results
Infinite turns.