Mairsil, the Pretender + Ventifact Bottle + Magistrate's Scepter + Staff of Domination

Mairsil, the Pretender

Ventifact Bottle

Magistrate's Scepter

Staff of Domination

How it works

1. Activate Mairsil using Ventifact Bottle's ability by paying 4 and tapping it, putting three +1/+1 counters on Mairsil.
2. Activate Mairsil using Staff of Domination's first ability by paying 1, untapping itself.
3. Activate Mairsil using Magistrate's Scepter's last ability by tapping it, gaining an extra turn after this one.
4. Move to your next turn.
5. Repeat.