Satoru Umezawa, Great Whale, and Walker of Secret Ways

Prerequisites

• Satoru Umezawa on the battlefield
• Great Whale in hand
• Walker of Secret Ways on the battlefield
• Walker of Secret Ways 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 Walker of Secret Ways as an attacker
2. When it isn't blocked, activate up to seven lands you control by tapping them, adding at least
3. Activate Great Whale's ninjutsu ability by paying and returning Walker of Secret Ways from the battlefield to your hand, putting Great Whale onto the battlefield from your hand tapped and attacking
4. When Great Whale enters the battlefield, it triggers, untapping up to seven lands
5. Activate Walker of Secret Ways's ninjutsu ability by paying and returning Great Whale from the battlefield to your hand, putting Walker of Secret Ways 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