Because she simply has no time to recover and accumulate.
From the very beginning, it has been a continuous output.
The Unity Realm blends with Heaven and Earth, endlessly regenerating, but that's just a metaphor.
Usually, she can manage a balance, converting Heaven and Earth Primordial Qi into True Qi at almost the same rate it is consumed.
Right now, that's not feasible.
Her recovery speed might be one, but her output consumption is three.
Unless she has some time to sit quietly and absorb Heaven and Earth Primordial Qi to fill her True Qi, she can't hold on.
But clearly, the enemy behind her won't give her that time.
So, this is a desperate situation.
Moreover.
She can still feel that inside her body, her internal organs are gradually giving out, as if turning completely into ice.
"Here, right here, even in death, I will go out with a bang."
