Atraxa, Praetors' Voice + Magistrate's Scepter + Contagion Engine

Atraxa, Praetors' Voice

Magistrate's Scepter

Contagion Engine

How it works

1. Activate Contagion Engine by paying 4 and tapping it, putting two charge counters on Magistrate's Scepter.
2. At the beginning of your end step, Atraxa triggers, putting a charge counter 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. Repeat each turn.