Archaeomancer + Erratic Portal + Capture of Jingzhou

Archaeomancer

Erratic Portal

Capture of Jingzhou

How it works

1. Cast Capture of Jingzhou by paying 3, taking an extra turn after this one.
2. Cast Archaeomancer by paying 2.
3. Archaeomancer enters the battlefield, returning Capture of Jingzhou to your hand.
4. Activate Erratic Portal by paying 1 and tapping it, returning Archaeomancer to your hand.
5. Move to your next turn.
6. Repeat.