Jill Valentine was still shaken by what had happened to Richard, her STARS colleague, as well as having had to fight off a literal giant snake. As the attic door closed behind her, she realised she also felt woozy.

"Am I.... Poisoned?" She asked herself as the world began to spin.

 Her legs felt like jelly, and she all but fell down the short stairwell and dropped to all fours, her body burning up.

"S-serum..." She gasped to herself as hot pains spread.

She tried to crawl, her legs feeling like they were melting, numb and yet boiling hot. Her skin itched, her clothing felt tight, and through blurry eyes she though her arm was turning green. With a groan that turned into a coughing fit, she felt herself hovering in and out of consciousness, barely aware of what was happening to her.

As she lay there, her pants began to rip, her legs expanding and starting to merge, scales growing on them. The hot flushes rapidly faded, a chill crossing over the feverish STARS member as the venom in her veins rapidly rewrote her DNA. Her upper body expanded too, and as her lower half's clothing ripped away to reveal a long serpentine like tail in place of legs, her growing torso expanded to both absorb her breasts while tearing off her shirt and bra. Scales replaced her sweating skin on her arms, her teeth and tongue elongated, and as her eyes opened and closed in fitful delirium, they shifted with each blink, turning to a bestial yellow that almost glowed.

Eventually, she passed out completely, now scaly green lids closing over the new yellow eyes, and there she lay. The woman she once was rendered into a snake with arms, only her beret and the tattered remnants of her clothes to show she had ever been anything but what seemed to be just another monster in the Arklay Mansion.

And after a short while, the new creature awoke, tongue flicking the air, the scent of possible prey lurking elsewhere. Her new fangs dripped with potent venom, the poisons as capable of rewriting DNA as the bite that the former Jill Valentine had sustained.

The naga-like creature began hunting, scales slithering over the floor as it began roaming the mansion.