Many of the adversaries in Undertale want to kill you so they can take your soul. But when you die — even to Asgore, who appears to know how to preserve souls — your soul cracks into pieces. This is different from the intact souls of the other children, and I take it to mean your soul is permanently destroyed (or it would be if you weren't able to SAVE). For example, Flowey's attack on Asgore's soul makes it shatter the same way yours does and that seems to be permanent.
Are there any in-universe or out-of-universe explanations for why the monsters were able to preserve the other children's souls, but not yours?
Best Answer
This seems to be either something for people to contemplate on, or a flaw in the design.
Here are my theories:
Hypothesis: The animation represents the soul being torn from the body. It is then reconstructed.
Evidence:
Evidence against:
Hypothesis: Frisk/Chara had a monster soul the whole time (Asrial’s soul)(still a human body).
Evidence:
Evidence against: