Ruby Rose

Ruby  is one of the main characters and the first character introduced in RWBY. Ruby's category of weapon is a High Velocity Sniper Scythe (HVSS) named Crescent Rose. She first appeared in the "Red" trailer released on November 5th, 2012, in which she fought Beowolves.

Appearance
Ruby appears as a young woman dressed in a red cloak, black blouse, and a skirt with red trimmings. Her entire apparel is made up of shades of red and black (hence "Red" Ruby). Even her hair is lightly red-streaked. On her waist is a belt on which large cartridges (possibly .50 caliber or comparable) are held in individual loops, a magazine pouch, and what appears to be a Latin cross (possibly Christian or Catholic iconography, or perhaps merely a decorative geometric design).

Initially Ruby resembles the Little Red Riding Hood archetype, and this is further reinforced by the appearance of the wolves, in this case the Beowolves. Directer Monty Oum has confirmed that she indeed alludes to but is not based on Red Riding Hood.

Abilities & Powers
Ruby is seen to be highly adept at using her scythe, Crescent Rose, single-handedly fending off a large pack of Beowolves without injury. She is skilled in both Scythe and Gun components, able to slice away at multiple opponents with blurring speed and accurately firing upon close- and long-range targets. She appears to be extremely quick to begin with, but due to her small stature, her already high agility is further increased by utilizing her weapon's recoil. Only a few times does an opponent come close to touching her, but she dodges, blocks, or counters the oncoming attacks.

Throughout the trailer, Ruby uses the recoil from Crescent Rose's shots to augment the speed and force of her strikes, although Ruby seems able to spin Crescent Rose with exemplary skill and power even without the recoil ability, and executes chain attacks often. Ruby seems supremely confident in combat, immobilizing an enemy for a moment to calmly assess the battlefield and other enemies before destroying her current target. She also uses the weapon itself as a platform from which to attack, as shown when Ruby laid down completely on the handle of Crescent Rose while firing at opponents.

In addition to using her weapon's recoil to make her more deadly in melee, Ruby also uses it to increase her manuverability. With regular ammunition, Ruby is able to disengage from close quarters to fight at range, or rapidly jump from range to close with an enemy.

The Cross Clips (technically magazines) Ruby uses near end of her fight are observed to be far more powerful than the unmarked magazines, giving her even more speed and power. With the more powerful ammunition, Ruby is able to use Crescent Rose to propel herself directionally with very great speed, and then rotate herself axially in midair to execute a devastating spinning slash attack.

 The following is fan speculation, and is not to be considered canonical.

Ruby's fighting prowess could be the result of Ruby herself being extremely light; or the recoil from Crescent Rose is incredibly powerful and Ruby possesses unusual strength; or Ruby has superhuman mastery of the ability to leverage Crescent Rose's ferocious kinetic energy to move and attack.

It is possible that she has some sort of power involving roses that is activated by emotion, as you see rose petals coming from her when she is standing in front of the Cliffside Altar and when she first starts the fight with the Beowolves. This could be further supported by the fact that the Beowolves dissolve into rose petals after being killed. But, this could have been simply artistic preference.

Trivia

 * She bears a striking resemblance to the famous fairy tale character Little Red Riding Hood. However, when asked by fans, Monty Oum stated that Ruby and the other girls will have no ties to any fairy tale at all. Although in a recent interview he did say Ruby's design was influenced by Little Red Riding Hood and that all the other characters' physical appearances will be majorly influenced by other fairy tales and mythological tales.
 * She was the first character seen in the series, appearing in a trailer released on November 5th, 2012.
 * Monty has confirmed Ruby being left handed; however, she is seen wielding with her right hand just as well, which stated by Monty is "common to switch both hands while fighting, especially to make it interesting."
 * It is unknown as of yet, but the Cliffside Altar seems to have some ties with Ruby. Possibly a monument from her past, or a grave marker for a relative or friend. If closely inspected, you can see it reads "Summer Rose. Thus Kindly I Scatter".
 * Her possible connection to the Cliffside Altar (which bears a resemblance to a grave marker as stated above) implies she could be a reaper of sorts. This is further enforced by her hooded cloak, as well as her scythe, both of which are associated with the Grim Reaper.
 * When Ruby uses the cross clips the muzzle flash turns black from the standard white.
 * While using her second Cross Clip she gains incredible, which allowed her to reveal a possible new form of her weapon, which looks like a claw, allowing her to do rapid spinning hits.