Mycosynth Lattice + Goblin Welder + Unwinding Clock + Mindslaver + Transmutation Font

Mycosynth Lattice

Goblin Welder

Unwinding Clock

Mindslaver

Transmutation Font

How it works

1. Activate any number of permanents by tapping them, adding at least 4.
2. Activate Mindslaver by paying 4, tapping and sacrificing it, causing you to gain control of the next person in turn order.
3. Move to the next turn. During that turn's untap step, untap all permanents you control due to Unwinding Clock and Mycosynth Lattice.
4. Activate Trasnsmutation Font by tapping it, creating an artifact token.
5. Activate Goblin Welder by tapping it, causing you to sacrifice the artifact token and return Mindslaver from your graveyard to the battlefield.
6. Repeat as long as you aren't next in turn order.