The Jolly Balloon Man + Magistrate's Scepter + Coretapper

The Jolly Balloon Man

Magistrate's Scepter

Coretapper

How it works

1. Activate The Jolly Balloon Man by paying 1 and tapping it, creating a token copy of Coretapper that is a 1/1 Balloon with flying and haste in addition to its other types.
2. Activate the token Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter.
3. Activate the token Coretapper's second ability by sacrificing it, putting two charge counters on Magistrate's Scepter.
4. 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.
5. Repeat each turn.