Activate Magistrate's Scepter, removing 3 charge counters to take an extra turn.
Activate Lithoform Engine, copying the extra turn ability.
Pass the turn.
At the beginning of your upkeep, Energy Chamber triggers, putting a charge counter on Magistrate's Scepter.
Activate Magistrate's Scepter, putting a charge counter on itself.
Activate Lithoform Engine, copying the trigger.
Pass the turn.
Repeat.

Infinite turns

Lock

Magistrate's Scepter

Energy Chamber

Lithoform Engine

Activate Magistrate's Scepter, removing 3 charge counters to take an extra turn.
Activate Tawnos, copying the extra turn ability.
Pass the turn.
At the beginning of your upkeep, Energy Chamber triggers, putting a charge counter on Magistrate's Scepter.
Activate Magistrate's Scepter, putting a charge counter on itself.
Activate Tawnos, copying the trigger.
Pass the turn.
Repeat.

Combos with "Energy Chamber"