I watched some Undertale fan videos for the past few days, and... one of them hit me like a brick.
It wasn't the Genocide route... if I ever play the game, I won't go there.
It wasn't the Neutral, or even the Pacifist ending.
The video showed afterwards.
Actually, there were three that hit me hard. (To make it easier to type, I will refer to Frisk in masculine, even if it's hard to tell what gender he or she really is.)
One showed events six weeks after the True Pacifist ending, after the barrier is lifted. The focus is on Sans, who still has trouble letting go of his nihilistic idea that Frisk would just end up causing a 'Reset' and everything would go back to how it was before. He essentially loses all composure and breaks down in front of Frisk, asking desperately when Frisk would 'Reset' everything... and Frisk simply replies that he won't anymore before giving Sans a kiss on the forehead.
The second and third are... kind of linked. It also takes place after the True Pacifist ending, but shows a battle-scarred Frisk. One has Frisk and Flowey wait for a bus to go back home, but Frisk lets it go by. Flowey says that the next bus will take twenty minutes to arrive, and Frisk seems okay about it. He then explains that he likes it when it's quiet for two reasons: one, it's always noisy at home, and he's always laughing... and two, he can't keep acting like he can't remember the past 'Resets'. He then asks Flowey for some quiet, to which the latter pulls out a handheld game console and starts playing.
The other focuses on Frisk and Sans. While Sans is glad and happy to see the outside world... Frisk isn't. When Sans tries to comfort him, he finds out that Frisk not only remembers every past 'Reset', but that he's traumatized for everything that happened... and that Frisk's timeline will soon end. Sans first tries to tell him that it'll be okay, only to be pushed away, until he finally figures that he and Frisk have the same problem - they remember, while everyone did not. To keep everyone else safe (and because he cares too much for everyone to 'Reset' to save his life)... Frisk uses the knife on himself, in front of a Sans who is too late to stop him.
I know that anime and video games often depict young hero characters fighting to fix mistakes of past generations, but... what happens when a hero completes his or her quest? What about the battle-scars and the painful memories of losing friends and family, or those of killing? Can children really erase something so serious as death from their minds?
I think the most impact-filled moment in a story that I remember now is in the last minutes of the last Lord of the Rings movie, when Frodo, Sam, Merry and Pippin are sitting at the Green Dragon Inn, looking at each other silently before lifting their pints to a silent toast. That moment said it all: each bore their scars, and each one changed. The battle was over, but... life would never really be the same.
I'm... honestly not sure what to add, so one last question for everyone: if you had the same ability as Frisk - to 'Reset' events up to a specific moment in time -, would you?