Not Yet

Unknown level, Unknown school

• Casting time: Mythic (1/Day), when reduced to 0 HP
• Range: Self (60-foot radius)
• Components: Unknown
• Duration: Instantaneous

When the Piper would be reduced to 0 HP, the performance refuses to end. He immediately returns to his full 285 HP. He also:

• Ends all conditions affecting him.
• Recharges Follow My Lead.
• Recharges Play, Piper, Play.
• Regains all spent Legendary Actions.
• Moves up to his Speed without provoking Opportunity Attacks.

Then every creature within 60 feet that can hear him makes a DC 17 Wisdom saving throw. On a failed save, it gains 1 Melody Mark. Phantom instruments erupt around the battlefield as the entire song begins again.

“You don’t stop the song just because you didn’t like the ending.”

Sources

Homebrew. An ability of The Piper. Used in 14-The Piper when we brought him to 0 HP, returning him to full.