Update: Riot have certainly outdone themselves on this champion as he has been revealed to be somewhat of a skillshot extraordinare that will require a lot of precision, a lot of quick decisions and hopefully will make an incredible tandem with his brother, Darius.

Abilities:

• Wicked Blades (passive) - Draven's Critical Strikes deal bonus physical damage over time. Spinning Axe also causes this effect even if it does not Critically Strike.
• Spinning Axe - Draven's next attack will deal bonus physical damage. This axe will ricochet off the target high up into the air. If Draven catches it, he automatically readies another Spinning Axe. Draven can have two Spinning Axes at once.
• Blood Rush - Draven gains increased Movement Speed and Attack Speed. The Movement Speed bonus decreases rapidly over its duration. Catching a Spinning Axe will refresh the cooldown of Blood Rush.
• Stand Aside - Draven throws his axes, dealing physical damage to targets hit and knocking them aside. Targets hit are slowed.
• Whirling Death (Ultimate) - Draven hurls two massive axes dealing physical damage to each unit struck. Whirling Death slowly reverses direction and returns to Draven after striking an enemy champion. Draven may also activate this ability while the axes are in flight to cause it to return early. Deals less damage for each unit hit and resets when the axes reverse direction.

Lore

 

Unlike his brother Darius, victory in battle was never enough for Draven. He craved recognition, acclaim, and glory. He first sought greatness in the Noxian military, but his flair for the dramatic went severely underappreciated. Thirsting for a method to share ''Draven'' with the world, he turned his attention to the prison system. There he carved out the celebrity he desired by turning the tedious affair of executions into a premiere spectacle.

Update Source : League Of Legends

After the arrival of Darius, the Hand of Noxus in the previous patch, Riot now tempts all players with this short teaser on its new upcoming champion - Draven, Darius' brother, a merciless gladiator, appearing shortly after his sibling's rise to power under Swain's guidance. 

There’s a saying in the entertainment business: “The show must go on!” When your particular niche in the world of show business is brutal, gladiatorial combat, however, this expression comes with its own set of limitations. Take Darius’ brother Draven, the Glorious Executioner. While he might be the consummate entertainer, this vicious champion of the arena is most famous for knowing exactly how it is that the proverbial show comes to an end – usually in some grandiose, blood-soaked fashion.

Source : League Of Legends