Requires

Rootha, Mercurial Artist must be on the battlefield. Reverberate must be in hand. Mana needed:

Steps

1. Cast an instant or sorcery spell, or wait for an opponent to cast one.
2. Holding priority, cast Reverberate by paying , targeting the spell.
3. Activate Rootha by paying and returning it to your hand, copying Reverberate, with the copy targeting the original Reverberate.
4. Resolve the copy of Reverberate, copying Reverberate, targeting the original Reverberate.
5. Repeat step 4.

Results