A slight Draven buff
Basically, I think it'd be fitting for Draven, being the loud, boasting glory hog that he is, to have his Theme start to play when he gets a kill streak going, and continuing on briefly afterwards.
That's about it- and yes, it would be a buff. As someone that generally plays with music on, having Draven's Theme start playing in the background would be a fantastic motivator ingame.