The comprehension
Xena emptied her mind.
In a normal situation, she knows how to fight blind.
If you could not use your eyes, you use your ears for the sound.
If you can not use your eyes and ears, you use touch to detect vibrations of the ground.
If you do not have all of them, then probably by smell.
If you can't even smell, then, hopefully, by taste.
If you do not have all these senses ? then how is it different from being dead ?
She had this experience when she went through the trial of time.
She was more sensitive than most people. Her ears could identify a ring of beel from a kilometer away, and she could differentiate two crows by their caws.
That's how ardently Xena had trained.
Caspian had been the love of her life.
She is aware of his smell, touch, appearance, sound of his voice, even the beating frequency of his heart.