Board Thread:General Discussion/@comment-26006155-20190425222457/@comment-26006155-20190612201315

Human souls have the power to save and load.

A monster with external Determination like Undyne does not.

The question was about Determination Extraction. Why Gaster pioneered it. And why Sans would object to The Darkest Experiment so strongly as to rebell against his best friend.

Deltarune is a future that happens... after the Barrier has been destroyed.

And only soul energy could have taken down that Barrier.

Did the True Pacifist ending happen according to Gaster's plan? It seems unlikely if, once acquiring Godlikely power, Hyperdeath Asriel's first priority (being controlled by Gaster) wasn't to break the Barrier, but to torment Frisk eternally by killing him over and over again.

The Darkest Experiment is what made Sans and Papyrus' trip to the past neccessary. And why their friend Gaster didn't come with them.