Riku of Two Reflections | Narset's Reversal | Twice Upon a Time // Unlikely Meeting

Cards

Riku of Two Reflections on the battlefield.
Narset's Reversal and
Twice Upon a Time // Unlikely Meeting in hand.
You control at least two Doctors.
({4} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({R} magic symbol) each turn available.

Cast
Twice Upon a Time by paying ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Riku's first ability triggers - choose not to pay.
Holding priority, cast
Narset's Reversal by paying ({U} magic symbol) ({U} magic symbol) , targeting
Twice Upon a Time.
Riku's first ability triggers, causing you to pay ({U} magic symbol) ({R} magic symbol) to copy
Narset's Reversal, with the copy targeting the original
Narset's Reversal.
Resolve the copy of
Narset's Reversal, copying the original
Narset's Reversal targeting
Twice Upon a Time, and returning the original
Narset's Reversal to your hand.
Resolve the copy of
Narset's Reversal created in step 5, copying
Twice Upon a Time and returning the original
Twice Upon a Time to your hand.
Resolve
Twice Upon a Time, causing you to take an extra turn after this one.
Repeat each turn.

You may pay an additional ({U} magic symbol) ({R} magic symbol) to copy the extra turn spell, and only need to do this loop during your second extra turn.