One last attack!
While using the Black Celestial Sword, which had turned into a bow, Layla needed to concentrate to not lose control of herself. Even more so now that she had just pulled out a Qi arrow, although it wasn't just any Qi arrow, it was one created from her life force.
For a long time, Layla had been holding the Qi of two people inside her, her own and her mother's, which she had received when the latter died. This allowed Layla to have a lot of Qi in her body, much more compared to the others.
Originally, Layla thought she would amount to nothing and had only gotten stronger due to two things. One, the Hannya form which Quinn had turned her into and the second was due to her mother's Qi.
Even now, she was using the celestial energy from the sword. However, Layla had been practising with her Qi endlessly during the years she had been with the red vampires. She not only tried to improve her sword skills, her Hannya powers and more, but also her Qi capacity.