The vampiress' fight with the mythic beast was mesmerising to the extreme, and may as well have been a work of art. Even with its jaw injured and reducing the number of bites per second the taniwha made, its gills and rapidly thrusting eyestalks more than made up for any deficiencies it might have had and the fact that Valentina was able to keep up was an incredible feat.
Had she been in a different form, it would have been inevitable that she would fall behind and get torn to shreds by the beast, but her 'Hannya's Resentment' not only made her physically more capable, but her reaction and processing speeds were also enhanced, letting the Archduchess just barely keep pace with the ongoing battle.