What did it feel like to be lost in one's own mind? To be awake yet asleep at the same time.
One could only imagine what it was like to constantly be trying to wake up forcefully, only to remain trapped in a silent coma.
Katari was not scared of the situation she found herself in, she wasn't fully aware of the state she was in. She couldn't tell the difference between a second and a day, they were both the same to her.
But even though she was mostly unconscious, her will remained. It was her will that held her mind up and allowed it to retain enough conciseness and desire to be awake.
Her constant push to be awake had also been accompanied by a hazy introspection, leading her to 'dream' constantly about the nature of her powers and how to make them better.
The desire to be better, enough to kill anyone who wanted to harm him.
"... Unfortunately, Isaiah still lives,"