If she still had the capacity for it, there would be many thoughts racing in Eliza's head - doubt and fear, regret for her actions, rage at Angela for making her infect herself, and maybe even awe at how effortlessly the Fuckbeast virus had reshaped her into the massive beast she now was. However, most of her mind was occupied by much simpler ideas: FUCK. MATE. REPRODUCE.
Her overwhelming arousal left little space for rational thought, and so it was more instinct than conscious reaction when she snapped after the vial she had jumped towards.
With a loud snap, the metal tube shattered in her mouth, releasing the nanites inside, and with an even louder crash, the giant panther landed from her jump, smashing a chair in the process. Meanwhile, the nanobots wasted no time and started to convert her almost immediately. A tingling feeling spread in Eliza's mouth, as if hundreds of ants were running around inside it, making her shake her head in irritation.
The first thing to change were her teeth. Enamel was replaced by razor-sharp steel, and her canines started softly crackling with electricity, hinting there was more to them than what met the eye. Her tongue was coated in shiny black rubber along with her lips and the inside of her mouth. Shortly afterwards, the feeling spread to the rest of her head, and her eyes turned into glowing blue orbs, retaining their feline pupils. Dizziness briefly overtook her as her brain was changed, but once it passed, the haze in her head lifted and she could think much more clearly than before.
Seemingly disinterested, Eliza looked back to watch the rest of her body change: Black rubber covered every part of her where high flexibility was necessary, while dull steel plating appeared wherever there wasn't. Her claws turned into metal, just like her teeth, but with sharp tips and a round, curved surface, making them ideal for grabbing onto anything from surfaces to prey, while her paw pads roughened up to allow for more grip, making them even less reflective than her steel components. Multiple vertical slits appeared along her flanks and started expelling hot air from her insides, while her mouth steadily began sucking in fresh air. Additionally, circular seams appeared on her back above the new exhaust ports, with extendable heat sinks forming underneath. Her oversized penis turned into to segmented steel and collapsed itself into her synthetic sheath, while her vagina was now lined by glistening rubber that seemingly secreted lubrication by itself. Finally, the tingling concentrated in her walnut-sized balls, which expanded until they started to stretch the rubbery skin surrounding them, after which the tingling slowly faded, signifying the new resting place of the nanites. Several jolts surged throughout her body, connecting her balls with every opening on her body to aid the spread of her condition, after which she only felt the soft vibration of her internals.
After taking in her new form for a while, Eliza let out a triumphant and deafening roar. She felt powerful - more than six feet tall on all fours, and a veritable killing machine made of rubber and steel, there was little that could stop her unless she allowed it. Excitedly, she looked around the room, her tail lashing behind her. Now she only needed to figure out what she wanted to do next.