Harbinger

Harbinger is Qrow Branwen's signature weapon. It is a large-bladed weapon that can take on multiple forms. He is first seen wielding it against Winter Schnee in "It's Brawl in the Family".

Overview
Harbinger is able to take on four forms. The first form shown is a single-edged greatsword with a clockwork mechanism of indeterminate nature built into the space above the hilt, and a pair of parallel handguards is set beneath. A pair of shotgun barrels are also situated on either side of the main blade, although it is unknown whether they are functional in this state. When swung, the sword appears to make a number of clicking and ratcheting sounds, but it is unclear whether this is significant or simply a sound effect.

The top half of the blade can be retracted into its base, forming a more compact portable mode, which is how Qrow normally carries Harbinger outside of battle. The hilt itself seems to contain some kind of control mechanism which serves to extend, curve, and retract the blade.

Harbinger has also been demonstrated to have a ranged mode, in which the blade folds forwards, making the shotgun barrels more prominent. The shotguns appear to be fired using a trigger in the hilt. The rounds have a buckshot-like spread.

In "Ruby Rose", Ozpin states that Qrow is an expert scythe wielder, being the only scythe wielder to match or exceed Ruby's skill. In "Burning the Candle", a silhouette of this form is seen in the flashback, which is wielded just like Crescent Rose.

During his battle with Winter, Qrow began the transformation to scythe form, but aborted the process and sheathed his blade before it could be seen clearly. During the transformation, the blade was shown to split into sections and fold backwards, briefly taking on a curved scythe-like shape while the clockwork mechanism in the hilt began to move.

During "Heroes and Monsters" the scythe form was finally revealed in full when Qrow used it to protect Ironwood from a Griffon. In the completed form the blade gained red sharpened edges on the inside, while the outer edge took on a serrated appearance due to the folding. The hilt telescoped in two places, which then curved much like a traditional farming scythe. A trigger, presumably for the shotguns, becomes prominent in the middle section of the handle. Interestingly, the transformation proceeded differently from before, with the entire hilt shifting instead of just the blade, and ending with the shotgun barrels in a different position. Concept art revealed in the credits implies that the shotguns can rotate independently of the rest of the hilt and of each other.

Trivia

 * A few bits of Harbinger were inspired by Bloodborne.