Board Thread:General Discussion/@comment-26006155-20190820122909/@comment-26006155-20191005004734

To Jacky https://undertale.fandom.com/wiki/Thread:172707#253

Sans makes several comments about "not being able to give it my all", knowing that time will be reset and they won't have any memory of it and such.

You're right that Sans hasn't been able to stop Flowey from saving and loading before. Which shows that, even though Sans has repeatedly killing Flowey, forcing him to reset, Flowey still has the greater determination.

But Determination isn't a static thing. Each time Frisk saves, it recharges.

And while countless monsters succeeded in shattering Frisk's soul again and again during the game, at The End, when everything mattered so much, Frisk was able to survive the rainbow-powered blast from a literal God... and tanked it with 0.0000001 hit points left.

Sans has suffered great lost, and been demoralized. He's no longer giving it 100%, and feeling crushing guilt from some of the things he'd had to do. He's no longer as Determined as he used to be.

But Frisk, realizing that the lives of everyone he knew and loved was at stake, was super-determined at the end, when facing Hyperdeath Asriel.

Determination isn't a static thing. It rises and falls, along with the amount of hope someone feels. That's why Frisk needs to keep getting Filled With Determination, when his energy runs low, and everything seems hopeless.

You also do bring up a good point.

Both Flowey and Sans have the ability to save and load.

And Flowey's power to do this, a power unique to human souls, did exceed Sans' ability each of those times Sans killed him, and it wasn't the end.

Flowey must have a human soul of some power in him.