Bond of Insight by paying ({3} magic symbol) ({U} magic symbol) .
Holding priority, cast
Turnabout by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) , untapping all lands you control.
Activate all mana-producing lands you control by tapping them, adding at least ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Bond of Insight, causing each player to mill four cards, and returning
Turnabout and
Twincast from your graveyard to your hand.
Repeat from step 2.
If lands you control can tap to produce at least ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) , this combo nets infinite mana, which can be used to infinitely cast instants instead of continuing to copy
Turnabout.
Results
Infinite mill.
Infinite self-mill.
Infinite storm count.
Infinite mana lands you control can produce.
Infinite magecraft triggers.
Put all instant and sorcery cards from your graveyard and library into your hand.
Infinite casts of instants in your graveyard and/or hand.