This is just a one-shot, based off an idea I got from reading one of Sexy Blue Eyed Devil's stories. It's called, "Devil's Scent" and it can be found in her section titled, "Taunt". Full credit for the pheromone idea goes to her.

I advise you to go read her writings, especially if you're a Vergil fan. They are very well written, entertaining, purr-material.

Now, before anyone gripes, she did give me permission to use her idea. See there? I asked already. So, hahahahahaha. Nyah. :p Kay, enjoy. Note: This story has mild sexual content, and poor Vergil is rather OOC. ;)

Vergil was nothing but a half-seen blue blur as he moved to cut down the offending demon. He felt a vague sense of concern when he realized that he would be too late. Not by much, but the damage would most certainly be done if she didn't react quickly. And she didn't see it coming for her.

In a flash of bright light, he triggered and attacked, shouting at her in a raspy, gravely voice. "Move! Quickly!"

She saw and was so horrified at his transformation that she almost didn't recognize his voice. It resembled his voice, yet it didn't. However, the advice was sound and she forced herself out of her shocked stupor. Snapping a look backwards, she saw she only had and instant to dodge the first swipe.

Vergil watched as the girl ducked and rolled to the side, just in the barest nick of time. Razor sharp talons slashed along the wall where her head and neck had just been, leaving deep gouges along its smooth surface. The force of the swing made the creature falter briefly, giving her enough time to scramble back even further out of reach. Roaring in frustration, the demon swiftly regained its footing and made to leap at its prey.

-Shing-

The creature screamed as Yamato slid effortlessly through skin and bone. Then again. And again. And again. Dozens of times in mere seconds.

She watched, mouth open in shock, as the demon abruptly stopped moving. It widened its eight eyes almost comically, regarded Vergil's Devil-form, then glanced back towards the girl. Just before it fell into several pieces, it managed to spray the human female with a fine mist of strange-smelling liquid.

"Oh, ugh! What the...fuck?!"" She leapt to her feet and started to frantically wipe at herself. As the mist enveloped her, she began to have a sneezing fit as well.

Devil-Vergil watched this show with a dim sense of amusement before he got a whiff of the substance that covered her.

Oh no.

Instantly, the devil reacted and lifted its head to catch the scent more readily. Forcing himself back to human form, Vergil had to struggle to remain composed. His other half, on the other hand, had no intention of holding back. He could feel the beast trying to resurface: twisting and questing under his skin. If that happened, he'd ravage the girl and she'd likely not survive.

"What is this shit?!" She shrieked, still clawing at her clothing. Her pretty features were twisted into a mask of revulsion.

"Pheromones," He answered, a bit breathlessly. "Demonic pheromones. Damnable creature." A low, rumbling growl of frustration, "This is precisely what I need."

He shook his head, trying to regain some sort of control when the human female began to back away. Instantly his eyes locked onto her, following her every move.

His demeanor had changed drastically and something about the way he was staring at her gave her sudden pause. Her brain didn't quite recognize the silent threat, but her body did. The girl became stock-still, instinct telling her not to make any sudden moves.

"Vergil? Are-are you alright?" She asked slowly.

The blue twin nodded, but waved her off with a hand. "Best go to your room now. Lock the door behind you. It isn't wise for you to be near me at the moment. Go bathe. Try to wash as much of that scent away as you can. Scrub your skin off if you have to. Go. Now."

She raised both brows, heart beginning to pound in her chest. His eyes were glowing and she could see his skin shifting back and forth between pale flesh and dark blue scales.

Another wave of lust swept over him and he suddenly glared furiously at her.

"Are you deaf?! GO! NOW!" He roared, eyes flaring bright green. His teeth had also elongated dramatically.

She jumped, more frightened of the way he was shouting at her, than of the partial triggering. Vergil had never lost control if himself like this. Not that she'd seen, anyhow. Backing away slowly, she kept a wary eye on him. He made no move to follow her, but his gaze was locked onto her every movement. After what seemed an eternity, she bumped into the door to her room and fumbled blindly for the doorknob, never taking her eyes off of him.

The girl slammed the door behind her and locked it, as he'd instructed. She eyed it doubtfully, rather certain that he'd be able to break it down if he was so inclined. As a further, but perhaps futile, precaution, she wedged the back of a chair underneath the door knob. She stood there for a few moments, breathing heavily and listening for any sound on the other side. There was nothing to be heard. Still though, just remembering the way his eyes had suddenly locked onto her sent shivers up her spine.

Oh, right! Shower!

Whatever these co-called pheromones were, she had to get them off of her. Clearly, they were the cause for Vergil's sudden, erratic behavior. Following his advice to the letter, she scrubbed at her skin until it stung. The girl stayed under the hot water for a very long time. When she finally emerged, she sniffed the air and herself, wondering if she had gotten enough of the scent off. Stuffing the soiled clothing into the hamper, she quickly threw on her nightshirt and retreated to bed.

The chair was still blocking the door and she relaxed a bit. Seemed that he'd regained enough composure. Good. That, and the fact that she was now clean, helped to further the calm. Despite the recent events, she was growing rather sleepy. Still though, she laid back and narrowed her eyes at the door, determined to keep watch throughout the night.

When she awoke it was completely dark. She frowned, still half-asleep. What had woken her up? Something was off. Something-

… There was a warm hand moving up and down her leg, and there was an unfamiliar weight and warmth resting next to her. Jerking in fright, she made to jump out of bed. An arm snaked around her waist and tightened slightly, effectively restraining her.

"Help," She whispered, chest too constricted with fright to manage a proper scream. "Vergil."

"Hmm?" There was a soft puff of warm air near her ear.

"Vergil?" Her eyes widened in the dark, and she felt blindly around. When her hand met the familiar material of his coat, she let out a gasp. "W-what are you doing?"

"Pondering your very immediate fate." His voice was an amused whisper.

"You need to leave," She responded, trying to sound firm.

He chuckled softly. Warm lips on the side of her throat began to dispense light, fluttering kisses. Slowly, they traveled down to where her neck began to curve into her shoulder. She felt a hand tug the collar of her shirt down to expose a shoulder. After a moment, she felt a warm tongue slide over it. A pleasant tingling sensation started to course up and down her skin. Without meaning to, she relaxed against him.

"You didn't scrub hard enough. I can still smell it on you, though it's not as potent as before," He murmured, nuzzling her hair. There was a deep intake of air and an exhalation that ended in a slight rumbling. "That and soap. And your natural scent as well. I like it much better than the perfume you usually wear."

His voice was deep and husky. A distinct difference than the frosty, tone she'd become accustomed to. A warm sensation began to bloom in her belly and she started to shake slightly.

Another intake of air, and his arm tightened around her again. "Now, you smell of lust. And fear. Just slightly, but it's there." A pause, "Are you attracted to me?"

"... Maybe." Truth is, she was. Had been for quite awhile, actually. But he was not himself right now and it would be wrong to encourage this. She had the distinct feeling that if she did, he'd be quite angry when he regained his senses.

Another throaty chuckle before she felt more soft kisses on her shoulder. The arm that encircled her loosened, and she felt him lift the hem of her nightshirt, exposing her legs and stomach. She let out a surprised gasp. Vergil took advantage of the distraction and pressed his lips against hers. The girl jerked in surprise, tensed, then relaxed again. He was encouraged, she wasn't exactly accepting it, but she didn't try to push him away either.

Dimly, he knew he shouldn't be doing this. Somewhere deep down, his oh-so-rational mind was shouting at him to stop this nonsense and leave the poor girl be. Unfortunately, the effects of the pheromones rendered coherent thought an impossibility. Physical pleasure was currently the stronger force and he was more than willing to give into it. He rolled on top of her and deepened the kiss, sliding his tongue against her lips, seeking entry.

Her heart was thundering and her skin was flush. She relaxed further and he let his weight pin her to the mattress. Vergil was solid and heavy. Much heavier than he should be, even for his size. And, at her acquiescence, his soft kiss became forceful and demanding. Growing alarmed, she issued a sort of muffled protest against his mouth.

Vergil broke the kiss and stared down at her with an arched brow. She could feel his gaze on her, even if it was too dark to see.

"Please. Stop. You're scaring me." Her voice was tiny and timid, almost beseeching.

Disappointment stabbed at him. There was a moment of considering silence, then, "What if I don't stop?"

The query was soft, but laced with undertones of menace. The implied threat was loud and clear. She realized that she had to proceed very, very carefully.

"Vergil, you don't act like this. You know you don't."

Silence. Then, she felt a hand deliberately squeeze first one breast, then the other. "No? Why not? I am a male, you realize. Given to bouts of lust just as any other would be." Still, he held that strange, threatening tone.

"Vergil Sparda!" It was a near shout and she felt him start slightly. Good. At least she had his attention. "If you don't take your hands off of me this very instant, I will never play chess with you again! Ever!"

Another silence. It felt like an eternity, but finally, he slowly removed his hand from her chest.

"Really?" He asked. Now he only sounded forlorn. Under any other circumstances, it would be amusing.

"Yes, really. You need to leave. This isn't you. This is whatever that stuff that got sprayed on me is making you do. And you're under contract to protect me. Remember? You gave me your word that you would. This isn't protecting me."

He lifted himself off of her and sat back on his knees, watching her carefully. She snatched her shirt back down immediately but made no other move to flee. No. That would certainly give him cause to chase.

Another eternal silence.

"I did, didn't I?" He asked, though to no one in particular.

"You did."

"You're a clever little human," He said. "And, you're right. I did promise."

She said nothing, just stared up at him mistrustfully.

"Alright, girl, you win. I will leave you be." Vergil got to his feet and she heard his footsteps going towards the door. "Though," he began thoughtfully, pausing at the entryway, "Next time I don't think you'll say no. Then all bets are off. I do hope you're durable enough. If not, then I shall most certainly break you."

He closed the door behind him, leaving her alone in the dark with her thoughts.