Sigil of the New Dawn + Coretapper + Magistrate's Scepter

Sigil of the New Dawn

Coretapper

Magistrate's Scepter

How it works

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.
3. Sigil of the New Dawn triggers, causing you to pay 1 to return Coretapper from your graveyard to your hand.
4. Resolve Coretapper's ability, putting two charge counters on Magistrate's Scepter.
5. Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, taking an extra turn after this one.
6. Cast Coretapper by paying 2.
7. Repeat each turn.