All permanents on the battlefield. Magistrate's Scepter has at least one charge counter on it. available each turn.
Kurkesh, Onakke Ancient + Magistrate's Scepter + Contagion Engine
Combo result
Infinite turns. Prerequisites
All permanents on the battlefield. Magistate's Scepter has at least two charge counters on it. {R} available each odd-numbered turn, with available each even-numbered turn.
Magistrate's Scepter + Contagion Engine + Doubling Season
Combo result
Infinite turns. Prerequisites
All permanents on the battlefield. Magistrate's Scepter has at least one charge counter on it. available each turn.
Combo result
Infinite turns. Near-infinite proliferate. Prerequisites
All permanents on the battlefield. Coretapper does not have summoning sickness. available each turn.
Magosi, the Waterveil + Nesting Grounds + Contagion Engine
Combo result
Infinite turns. Prerequisites
Nesting Grounds and Contagion Engine are on the battlefield. Magosi the Waterveil is on the battlefield with an eon counter on it. Both lands are untapped and you have not yet made your land drop for the turn.