Ba Sing Se + Phyrexian Altar + Stone-Seeder Hierophant + Zirda, the Dawnwaker

Ba Sing Se

Phyrexian Altar

Stone-Seeder Hierophant

Zirda, the Dawnwaker

How it works

1. Activate Ba Sing Se's second ability by paying due to Zirda and tapping it, earthbending another land you control.
2. Activate Phyrexian Altar by sacrificing the other earthbent land, adding .
3. When the land dies, Ba Sing Se triggers, returning the land from your graveyard to the battlefield tapped.
4. When the land enters, Stone-Seeder Hierophant triggers, untapping Stone-Seeder Hierophant.
5. Activate Stone-Seeder Hierophant by tapping it, untapping Ba Sing Se.
6. Repeat.