Fanny was a liar.
First, she tricked Hela into believing she was her, and then she tricked herself into thinking she was Hela.
The soul remained the same, but if another person's memories and character were stuffed inside the brain, another personality would occupy a region of the original owner's brain.
She lied to herself for a hundred years.
But she couldn't fool Hela.
In fact, she deceived Hela for a short time.
But when Hela saw Hewitt, she remembered who she was.
Fanny was not an extremely evil person who wanted to destroy all life, subvert civilization, and commit all kinds of evil deeds.
What she sought and longed for was actually what everyone wanted - a happy life.
However, she never had it from the beginning, so she would do anything for it, even though she still knew that her actions were sinful and deeply guilty.
Meanwhile, she persisted resolutely.