Lands you control can tap to produce at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Steps
Activate any number of lands you control by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Cast
Turnabout by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) , untapping all lands you control.
Timeless Witness enter the battlefield, they trigger, returning
Turnabout and
Ghostly Flicker from your graveyard to your hand.
Repeat.
Notes
If lands you control can tap to produce at least ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) , this combo nets infinite mana. You can then stop casting
Turnabout and blink one other permanent using
Ghostly Flicker. You may also tap artifacts and/or creatures instead for mana if desired.
Results
Infinite LTB.
Infinite ETB.
Infinite storm count.
Infinite magecraft triggers.
Infinite blinking.
Infinite landfall triggers.
Infinite mana permanents you control can produce.
Infinite untap of permanents you control.
Target opponent returns all cards in their graveyard to their hand.