|“||The Key is what will cause salvation, that salvation doesn't have to benefit humanity||”|
–Kotarou speaking to the voice in Akane's Route
Salvation is an event brought upon by the Key to wipe out humanity. This is to ensure that the planet continues to contain aurora in it. It is initiated by the Key singing the Song of Destruction, either through forcing it to her or her singing it to her own accord. In the process, the Key slowly transforms into a tree.
The means of stopping Salvation is to either kill the Key or show her a good memory. However, the former cannot stop humanity from dying out due to the continuous depleting of Earth's resources.
In the story, Gaia desires Salvation, while Guardian seeks to prevent it. This ideological conflict has caused wars between the two organizations. The Druids, despite their role to worship the Key, have little idea on what it is.
As explained in Moon Route, Salvation is intended to happen for re-evolution (再進化 saishinka) to occur. This is so that aurora can flourish once again after it once reached a critically low point.
At one point, the Earth's aurora was depleted to a point where re-evolution became impossible. Moon Kagari then took the remaining aurora from Earth and constructed the Theory of Life, to research a way for humanity to surely survive. The finished Theory became the foundation of Terra Route's timeline. Because re-evolution could no longer happen, Kagari desperately wanted a good memory so humanity can survive.
In Shizuru Route, Common Route's bad end, and a simulation in Moon Route, salvation causes all the people on the planet to vanish into thin air while being oblivious to what is happening around them. In these cases, the Key invoked the Song of Destruction without anyone forcing her.
In Akane Route and the Terra Route, where Gaia forced the Key to sing, salvation causes natural disasters around the world: volcano eruptions, tsunamis, earthquakes, and hurricanes as well as the forest devouring everyone and everything on land. As depicted in the Anime-Original Route, this will also eventually lead to humanity vanishing into thin air.
All Salvations that have been portrayed in the anime adaptation shows everything being devoured by the forest. Also, glowing pieces of what is presumably aurora coming from disappearing people and the surroundings ascend to the sky.
At some point before the current events of Rewrite, the Key exploded and destroyed an entire continent.
- Salvation is supposebly the most powerful ability in Rewrite; its more considered to be a type of armageddon.
- Sakuya and Kotarou survived salvation by 'rewriting' themselves into trees, because salvation's weapon for destroying humanity is nature it did not affect them.
- Salvation seems to only destroy what is on the surface of the Earth; Shizuru and some other humans were able to survive by moving into a facility that was underground.