Ba Sing Se, Phyrexian Altar, Stone-Seeder Hierophant, and Agatha of the Vile Cauldron

Prerequisites

• Ba Sing Se on the battlefield
• Phyrexian Altar on the battlefield
• Stone-Seeder Hierophant on the battlefield
• Agatha of the Vile Cauldron on the battlefield
• available

Steps

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

Results

• Infinite LTB
• Infinite death triggers
• Infinite landfall triggers
• Infinite sacrifice triggers