Suggestion - Which blue support gem to socket?

So I have this personal Scion build... it's doing well so far, almost 3.4k dps at level 38 but it's missing something. Don't get me wrong it's fast and easy to play, but a bit less fun than I anticipated.

Is there a blue support gem which my character can use? Do more AoE damage, or inflict damage over time like affliction? What could I socket with SWEEP?

Unless you are doing elemental conversion with your build, get rid of Faster Attacks and Added Fire. Instead, I'd play Impale and Brutality.

If you play crit at all, I would do Increased Crit Strikes for the blue socket.