Rewind Spring

The Rewind Spring is a location that debuted in Kid Icarus: Uprising. Appearing in Chapter 22, it is a magical spring located within the Underworld.

Abilities
The Rewind Spring has the ability to reverse the effects of time on anyone who comes into contact with its waters. However, if a being spends too much time submerged, it has the potential to reverse time undesirably, even to the point of erasing their entire existence.

Chapter 22: Scorched Feathers
After Pit sacrifices himself to save Dark Pit, the latter travels through the City of Souls in order to reach the Rewind Spring and reverse the damage on Pit's wings.

Once Dark Pit arrives and approaches the spring, Pandora suddenly separates from his wings and dives into the water, restoring herself to her ghostly form. Dark Pit and Pandora engage in a brief battle before Pandora decides to submerge herself in the spring once again, which transforms her into her humanoid form, Amazon Pandora. She continues to fight Dark Pit, boasting to the other gods about her new appearance, before Dark Pit manages to defeat her once and for all.

Afterwards, Dark Pit carefully dips Pit's wings into the spring, which reverts the damage and heals him. Once Pit awakens, Dark Pit attempts to fly away, but fails as he no longer possesses Pandora's Power of Flight. Viridi grants him flight herself, and Pit and Palutena reunite before the goddess teleports him back home.

Idol Description
''Any creature that soaks in the Rewind Spring can roll back the effects of time. And at first glance it does seem like the spring reverses aging, thereby bestowing immortality. Yet those who stay for too long may find their entire lives erased.''

Trivia

 * The Rewind Spring is likely based on the Fountain of Youth, as they are both magical springs with restorative powers.