Satoru Umezawa, Palinchron, and Skullsnatcher

Prerequisites

• Satoru Umezawa on the battlefield
• Palinchron in hand
• Skullsnatcher on the battlefield
• Skullsnatcher does not have summoning sickness and cannot be blocked by an opponent
• You control up to seven lands that can tap to produce at least

Steps

1. Declare Skullsnatcher as an attacker
2. When it isn't blocked, activate up to seven lands you control by tapping them, adding at least
3. Activate Palinchron's ninjutsu ability by paying and returning Skullsnatcher from the battlefield to your hand, putting Palinchron onto the battlefield from your hand tapped and attacking
4. When Palinchron enters the battlefield, it triggers, untapping up to seven lands
5. Activate Skullsnatcher's ninjutsu ability by paying and returning Palinchron from the battlefield to your hand, putting Skullsnatcher onto the battlefield from your hand tapped and attacking
6. Repeat from step 2
7. If you control up to seven lands that can tap to produce at least , this combo nets infinite mana

Results

• Infinite ETB
• Infinite LTB
• Infinite mana lands you control can produce
• Infinite untap of lands you control