[She comes down in a rush and a clang from her armor plates solidly connecting with each other and the floor, ready to race after him in this chase of cat and mouse... but realizes too late in her dash what he intends to do with this dark spell, rather than attack directly. She curses under her breath, but doesn't try to dodge; there's no dodging magic meant to affect something that is separate yet still part of you, a part you have no sway over. The pure ever drives away the shadows, but just the same the deep dark can smother the light with ease, and though her class resistance grants her immunity against near all sorcery of the current era, he's no modern magus, one of those weakened conjurors lurking in the twilight of their prime and clinging to the last remnants of pride.
Like water against rock, her small figure jerks in abrupt halt as her face twists in slight pain but more stubborn resistance, she'll be dammed before he has her. Gritting her teeth tightly, she throws all she can in the direction forward, holding her sword upright in front of her unwaveringly still as she yet tries to move her shoulders and arms and get some momentum for her upper half. The crackling and hissing of something like burning can be heard, while every ounce of mana she can spare is poured into her limbs and spent, forcing her legs to motion and reinforcing them beyond her physical limitations-- because sure enough, you can't hope to match magic with the physical alone-- and her strained groans grow into a low, unchecked roar as she makes one step, then another.
It may feel like she's accomplishing little more than tearing her muscles apart and ligaments right from bone now(and perhaps actually is, she'll heal easily enough though), but once she can get the binding to give, she'll be in the clear]