Satoru Umezawa, Great Whale, and Moonsnare Specialist

Prerequisites

• Satoru Umezawa on the battlefield
• Great Whale in hand
• Moonsnare Specialist on the battlefield
• Moonsnare Specialist 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 Moonsnare Specialist 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 Moonsnare Specialist 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 Moonsnare Specialist's ninjutsu ability by paying and returning Great Whale from the battlefield to your hand, putting Moonsnare Specialist onto the battlefield from your hand tapped and attacking
6. When Moonsnare Specialist enters the battlefield, it triggers, returning up to one creature to its owner's hand
7. Repeat from step 2
8. If you control up to seven lands that can tap to produce at least , this combo nets infinite mana

Results

• Infinite ETB
• Infinite LTB
• Return any number of creatures to their owner's hand