Ruby Rose, Her New Cock, and an Ero System (A LitRPG RWBY AU)

9. Boss Fight

Yang's bunnysuit expired half an hour later in a puff of pink smoke—in the middle of a fight. Her sister's naked body was once again revealed to the world, and was twice as flustering since Ruby had been briefly shielded from it.

When the fight came to an end, neither of them commented on Ruby's erection. She was seriously growing tired of how easily it gave away her thoughts. At least Yang was good at pretending she wasn't seeing anything. At pretending she didn't notice her little sister lusting over her.

Seriously, what was wrong with Ruby? It didn't matter how amazing Yang's body was: they were sisters. Those thoughts were firmly not allowed.

"Thank the gods for that," Yang said, looking down as she bounced on the balls of her feet. Ruby tried not to pay attention to what the bouncing did for Yang's assets. "Those heels were killing me. So glad they're gone."

There wasn't much more to say on the topic, so they continued forward. The Rift went on. And on. And on. Her aura waned, as did Yang's.

A part of her started to wonder whether the Rift wanted something from them, and whether it would keep infinitely generating rooms until some hidden criterion was met. That wasn't how Rifts were supposed to work. They were supposed to have finite, if sometimes enormous amounts of rooms, but be static upon creation.

But this one was turning out to be so absurdly large, especially for a first-timer Rift, that Ruby contemplated other possibilities.

Just as she was about to broach the subject with Yang, they came upon the final room, axing her growing theories.

The end of the Rift was, of course, identified by the exit portal. Unlike the one they had come in through, the rend in reality was a thin line of vibrating purple-black energy cut into the air, not a full ovular two-dimensional shape like the entrance. If they wanted to open the exit, they had to fight and kill the final encounter, which was always the hardest of the Rift.

The final encounter—the boss—was what drew Ruby's eye more than the exit portal.

Because.

Uh.

Why did this Grimm look like a person?

The Grimm—the…Grimmgirl?—sat on a black throne on the far end of the room, legs crossed, head on one hand, seeming bored. Crimson eyes locked on Ruby and Yang, who stood on the opposite end of the cavern, weapons drawn, staring in disbelief.

The Grimmgirl was naked, same as Ruby and Yang. She had two short black horns protruding from her head, the key feature that screamed Grimm. But also her unnaturally pale skin, nearly bone-white, and the black and red tattoos adorning her body and face. She wore her white hair done up in a bun.

Black and red tattoos. Did that mean she was E-Rank or higher? That she was stronger than the previous Grimm was a given, with this being the final encounter, but an E-Rank? She and Yang weren't equipped to handle an E-Rank, much less after a full day's grueling expedition.

Somehow Ruby doubted whether the typical Grimm ranking methods applied here, though.

Because by the woman's sheer presence…E-Rank wasn't remotely accurate. Even from thirty yards away, an aura of danger crushed into Ruby, a warning her hindbrain acknowledged, even if there were no visible threats of danger.

"Ah," the Grimm said, and her voice echoed across the room, despite how soft the words were spoken. "You're finally here."

"Yang," Ruby hissed. "Yang, there's a Grimm talking to us."

Yang was pale-faced, with Ember Celica raised in a defensive posture. Cool as a cucumber she might be in most situations, but this was something even she couldn't pretend wasn't insane.

"I'm seeing what you're seeing, Rubes," she said tightly.

"First evolutions, though?" the Grimmgirl continued, shifting on her throne, remaining bored—her expression hadn't changed in the slightest, a placid mask. "That's unexpected. I was wondering why I was called here, and this confuses me further. Something strange is going on."

Well, she wasn't the only one who thought that.

"Yang," Ruby repeated, with increasing urgency. "A Grimm is talking to us."

"Grimm can't talk," Yang said with the sort of disbelieving certainty she might if she'd said, 'Pigs don't fly.'

"Are you saying that isn't a Grimm?" Ruby asked.

"That's definitely a Grimm."

"Well, it's talking to us! So!"

"Grimm can't talk," Yang repeated.

Ahead, the Grimmgirl sighed and finally broke her pose of boredom and stood. She was tall, especially for a woman, probably over six feet. She strode forward, descending the four steps of the platform that elevated her throne from the rest of the mundane-looking cavern. Ruby and Yang kept their weapons drawn and ready, too confused to think properly, but ready to react with violence, as any huntress would be.

"I think I understand," the Grimmgirl said, looking at Ruby. "Your eyes. That explains part of it." Her attention flicked down, and her brow furrowed slightly. "Your particular manifestation of power … that's curious, though." She shrugged. "Still, you are first evolutions. Nobodies. Unrealized potential means nothing to me." She came to a stop after a handful of steps, tilting her head as she scrutinized them. Then she shrugged. "I'll be seeing you again, I'm sure. For now, prove yourselves."

Ruby had just begun working up the nerve to respond, but the Grimmgirl apparently didn't care for a dialog. She raised a bone-white hand toward Ruby, which made both her and Yang tense. But rather than conjuring some magical bolt of black magic, a swirling pool of liquid appeared in front of the Grimmgirl. Unlike the portals, it didn't vibrate with purple streaks of energy. It was thick as tar. Viscous fluid clung to the beast that emerged: a proper Grimm. Perhaps fittingly, the same type as they'd encountered in their first fight this Rift. A Beowolf.

And not an F-Rank. The monster sluggishly rising from the black liquid had streaks of red marring its bone plating. An E-Rank. The match of a second- or third-evolution huntress. A completely absurd challenge to end a Rift this size.

Instantly, Yang's confusion melted away, replaced with intensity. "E-Rank," she said. "You got those bullets handy?"

"Y-Yeah."

"Time for you to use them."

Ruby nodded.

In most cases, a fight against an E-Rank Grimm would mean certain death. She and Yang were good, but only human. And exhausted from a day's worth of fighting. With bullets packed with Pink Dust, though? The first had made an F-Rank Grimm's skull disappear in a single shot. The firepower granted through her second class might close the gap.

Ruby wished she could have talked to the Grimmgirl, to have found her voice before she'd lost interest and summoned the Grimm, but she hadn't. The experience had been too strange. Now, the pale-skinned, horned woman walked back to her throne and took a seat, expression as bored as before. The E-Rank, however, snarled and crouched, making its intent clear.

Yang charged first, not ceding the first strike. Crescent Rose transformed a millisecond afterward, crashing down into her sniper-rifle form. Ruby's shot was lining up even before Yang and the beowolf had finished closing the distance.

Her first shot landed true, the beowolf's trajectory easy to predict. A Pink Dust-empowered bullet took the beast on the skull. Unlike the first time, its head didn't simply disappear. That was partially thanks to the bullet having a lower quantity of Pink Dust, the rest of the crystal spread out among six bullets, but more importantly, because of the Grimm's sheer resistance—that they were outclassed. A first-evolution huntress, or a pair of them, shouldn't be facing an E-Rank.

The bullet did, however, shatter the beowolf's armor plating, enough force behind the bullet to halt its charge and make it go staggering sideways.

Pink Dust was no joke.

The raw firepower caused issues for Ruby, too. It didn't matter how much she braced herself, how completely she wrapped her aura around her body and readied for impact. The kickback of a Pink Dust bullet, even diluted compared to the first, made Crescent Rose fling upward, and Ruby go staggering backwards. Nearly a second passed before she'd steadied her weapon and brought her eye to the scope again. Which was an eternity in aura-enhanced combat. Yang had already closed the gap and begun to brawl.

A part of Ruby took note that the bullet hadn't produced a 'side-effect,' which had been a working theory of hers—that it was chance based, likely influenced by the amount of Pink Dust crammed into the mixture, and maybe other factors. Of course, this was the smaller, academic, weapon-enthusiast part of her paying attention to that. The majority of her attention was on the life or death fight. On the fact that her sister needed help.

The next shot was harder to land. With the beowolf and Yang locked in physical combat, her blonde-haired sister weaving between snarling swipes and chomps to deliver punches that barely fazed the monster, finding an opportune moment to sneak in another high-powered bullet was difficult. Especially since hitting Yang would have devastating consequences, more so than even if she'd been working with regular ammunition. She had to be double careful. Again, Pink Dust was no joke—Yang wouldn't fare well if one hit her.

But Ruby was, if not a pro, someone who'd been training for this her entire life. She might not have known her weapon would manifest as a sniper rifle, but she'd always loved firearms. Had plenty of practice with them.

She opted for an easier target than the head. Her next bullet pierced the Grimm's side, a center-of-mass shot. The third bullet did likewise. The fourth, she found another opening for its skull, further shattering the bone plating. Fifth was a miss, which Ruby chided herself for. Sixth caught the beowulf on its back leg, blowing the bottom half of the limb clean off.

But then she was out of bullets, and it was time to join the fray.

Yang had occupied its attention wonderfully, but was clearly growing harried. She might be one of the best fighters Ruby had ever seen, at least among their peers, but there was only so much she could do against an opponent so much stronger and faster than her. Her aura had nearly broken; Ruby could tell that at a glance. She was flagging.

So was the Grimm. But honestly, despite its missing limb and cracked skull armor, it looked healthier than Yang. By a good margin.

This was going to be close.

Ruby dashed across the stone cavern, sparing a glance toward the bored Grimmgirl on the throne, who watched the combat with impassivity. She seemed neither impressed nor disappointed in their performance so far. Ruby worried whether she would join in, or worse, summon another E-Rank Grimm after they killed this one. If so, they were screwed.

But surely not. That wouldn't be fair. Then again, this Rift already wasn't fair, and there'd been so many strange things happening that she had no clue what else might.

Ruby engaged the beowolf, which bought her sister a reprieve as its attention turned to her. The beast swiped, but she disappeared in a puff of petals to slam her scythe down toward its exposed flank. Shadows exploded from where the blade gouged into flesh, though the injury was less severe than what an F-Rank Grimm would've suffered.

Even with [Petal Form], Ruby struggled to keep up. It gave her a new appreciation for how expertly Yang had been occupying its attention, because wow, it was fast. And strong.

Unlike Yang, Ruby wasn't all that durable. One good hit might take her out. She had to be careful.

They traded a handful of blows before, maybe as was inevitable, Yang slipped up, and a paw caught her on the stomach. The last of her aura reserves cracked, a sensation audible to Ruby's sixth sense, and Yang flew away, knocked unconscious.

Ruby shoved down the panic, as thick and intense as it was. She was a huntress-in-training; seeing an ally hurt, even her sister, couldn't break her composure. Not when there was a rampaging Grimm in front of her.

It was weak and flagging by now. Yang's efforts hadn't been wasted. The openings she'd given Ruby had paid off. She just had to finish the job.

In a burst of petals, she flew toward the beowolf, ready to do just that.