Mischievous Quanar on the battlefield (face down).
Lands you control can tap to produce at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
It is an opponent's turn, after their upkeep step.
Steps
During an opponent's turn, after their upkeep step, activate all lands you control by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Holding priority, activate Mischievous Quanar's morph ability by paying ({1} magic symbol) ({U} magic symbol) ({U} magic symbol) , turning it face up.
Mischievous Quanar triggers, copying Reset.
Resolve the copy of Reset, untapping all lands you control.
Activate all lands you control by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Activate Mischievous Quanar by paying ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) , turning it face down.
Repeat from step 3.
If lands you control can tap to produce at least ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) , this combo nets infinite mana, which you can then use to activate Mischievous Quanar to get infinite copies of any other instant and/or sorcery spell(s) on the stack.
Results
Infinite copies of any instants and/or sorceries on the stack.