Satoru Umezawa and Sakashima's Student on the battlefield.
Sakashima's Student 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 ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) .
You control at least one additional nonlegendary creature.
Steps
Declare Sakashima's Student as an attacker.
When it isn't blocked, activate up to seven lands you control by tapping them, adding at least ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) .
Activate Palinchron's ninjutsu ability by paying ({2} magic symbol) ({U} magic symbol) ({B} magic symbol) and returning Sakashima's Student from the battlefield to your hand, putting Palinchron onto the battlefield from your hand tapped and attacking.
When Palinchron enters the battlefield, it triggers, untapping up to seven lands.
Activate Sakashima's Student's ninjutsu ability by paying ({1} magic symbol) ({U} magic symbol) and returning Palinchron from the battlefield to your hand, putting Sakashima's Student onto the battlefield from your hand tapped and attacking as a copy of any nonlegendary creature you control.
Repeat from step 2.
If you control up to seven lands that can tap to produce at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({B} magic symbol) , this combo nets infinite mana.