Narset's Reversal

Cards

You have an additional instant or sorcery card in hand with valid targets as applicable.

({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough mana to cast the additional instant or sorcery available.

Cast any instant or sorcery by paying its mana cost.
Holding priority, cast
Twincast by paying its mana cost, targeting the instant or sorcery cast in step 1.
Cast
Narset's Reversal by paying ({U} magic symbol) ({U} magic symbol) , copying
Twincast targeting the spell cast in step 1 and returning the original
Twincast to your hand.
Cast
Twincast by paying its mana cost, copying the copy of
Twincast, targeting the copy of
Twincast.
Resolve the copy of
Twincast, creating a copy of
Twincast targeting the copy of
Twincast.
Repeat step 5.

This combo has been estimated to be Exhibition (Bracket 1+).