It´s ok. I mean, I didn´t exactly describe my OCs all that well. My Bad.
Anyway, I guess I´ll just fix this little mistake of mine now.
Argent Star is a snake faunus, with his faunus trait being a tail he can use pretty much like Tyrian uses his. The biggest difference there is that Argent´s tail is strong enough to crush basically any rock he can completely grasp with his tail.
His weapon of choice is a pair of wrist-mounted extendable short swords that can be imbued with dust to get various effects. The left one can also become a shield, while the right one doubles as a chain whip.
His semblance allows Argent to burst into a cloud of fog, allowing him to move without being noticable. He can also just evaporate partially, giving him an edge in combat as he knows everything going on in the fog, allowing him to dodge surprise attacks from professional snipers without even facing their direction.
Argent mostly specializes in swift, yet powerful, attacks, as well as quickly changing from close- to medium-distance combat and back. If he´s too far away from an opponent to attack, or when the opponent catches him off-guard, he evaporates to cover the distance and confuse his opponent. And, if all else fails, he can combine his semblance with dust.
Niob Bolt is a bat faunus, and his faunus trait is a pair of wings. While they can´t take him off the ground easily, he had them imbued with ice dust before going to Beacon, so he can shoot ice darts from them, coat them in ice to block attacks, or have objects freeze onto them.
His weapon of choice is a pair of dual-weilded short swords that double as fully automatic pistols. He also has a pumpgun that doubles as an axe (both one handed and two handed, depending on which he needs), as well as fake vampire teeth in his mouth that he imbued with fire dust, allowing him to breathe fire or spit them out and use them as mine. He also has a pair of shuriken launchers hidden in his sleeves, each holding 2 dust-imbued shuriken that move too fast for the human eye, giving off the impression he just had to point at something to make it explode in a giant lightning ball.
His semblance allows Niob to make shaows come to life when he touches the object, or being, casting the shadow. Both the shadow and the original need each other to exist, meaning that if one dies, the other dies, too. He mostly uses his semblance against Grimm, as a huntsman´s aura blocks the effect completely.
In combat, Niob follows a similar tactic as Batman, namely intimidating his opponents to finish them off more easily. He is a considerable threat at any distance, even if one does not know about or believe the rumors of him being a vampire. He´s not, but if people believe he was, they don´t mess with him, so he keeps up the facade.
Sirena Blue is a stonefish faunus, and her gills allow her to breathe under water without any problems.
Her weapon of choice, a golden telescope trident that can turn into a scepter with a red orb on top, was designed by Niob when he was bored, and he gave it to her since he didn´t need it as much as she did. Prior to that, she used a regular pitchfork. It can hold up to three vials of dust, usually two water and one ice, and she can shoot the dust in its elemental form from the three spikes of her trident.
Her semblance allows her to intoxicate other beings by mere physical contact, and while it originally only paralyzed the victim, she quickly learned to change the effects of the poison. She can also combine her semblance with dust, mostly using water dust to become so slippery that every attempt at melee combat fails. The poisonous effects of her semblance are blocked by aura, but the victim´s aura takes considerable damage, based on the type of poison she produces at that moment.
In combat, Sirena mostly carries herself with a certain elegance reminiscent of royalty. However, when a fight becomes personal, like when she is defending her honor, someone insults her home kingdom (it´s under water, btw), or when another silver eyed warrior is in danger, even her teammates keep their distance. Her fighting style becomes more aggressive, offensive and direct, but not less calculated and, you guessed it, toxic. She is a strategic genious, able to beat almost the entire Beacon staff in Remnant: The Game. Ozpin always refused her challenge, since he had better things to do.
Talia Star, Argent´s little sister, is a mouse faunus, and her trait is a tail as well. Yeah, their mom´s a lion faunus, and their dad´s a mosquito faunus.
She doesn´t have any weapons of her own, but she can use her fists, feet and tail in meele combat, and her mind is sharper than any katana. She stopped growing at a rather young age, making her look younger than Ruby, while in reality, she´s just a year younger than the rest of her team, and they graduated three years prior to the series. She uses her child-like appearance to great effect, mostly to fool others into thinking she was just an overly oblivious child. This gives her time to study her surroundings, as well as her opponents and any bystanders, and when a fight is unavoidable, she can fall back on her knowledge of martial arts, as well as her abbility to process virutally any information ten times faster than any computer. When she hears a gunshot, she can almost immediately tell the model and the distance, allowing her to predict the bullet´s path and block it with relative ease by using her tail like a baseball bat.
Her semblance allows Talia to turn into a ghost, meaning that she becomes invisible and intangible, thus being freed from gravity and such. In this state, she can posess inanimate objets, such as scrolls, to send herself all across Remnant and literally copy/paste knowledge directly into her brain. She can also posess dust, which allows her to control the vary forces of nature around her. For this very purpose, she always carries a few earth- and air dust crystals around.
In combat, Talia is basically like she always is: Fast, energetic, and problematic. She mastered over 20 martial arts in record time (remember the "copy/paste knowledge directly into her brain" part?), and has developed her own fighting style based on what she saw in the Vytal Tournament. Should an opponent get out of her reach, which is a very common problem for her, she simply turns into a ghost, walks up to the opponent and rematerializes, before she starts covering them in an endless barrage of punches, kicks and tail thrusts. And, if all else fails, she can posess the air or earth around herself. She may have copied that trick from a Geist...
Back at Beacon, the four of them, Team ANST, would often fight against one another in 1-on-3 matches. They actually did that every day, unless they were on a mission, and each week, another one of them would take the place of the one fighting the other three. This let all three of them become very skilled in combat, as well as allowing them to fight a greater number of opponents, as well as opponents who are able to take down various enemies at once.
Also, about Tyrian giving Qrow a run for his money: I think Qrow didn´t want to defeat Tyrian, but simply allow Ruby and the others to escape.
And if Ruby hasn´t been there, I´m pretty sure Qrow would´ve won.