Narset's Reversal + Reverberate

Prerequisites

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

Steps

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