6) Thea Kicking Ass
After Thea whined her way through seasons one and two, which to be fair was mostly justified, Oliver’s sister came into her own at the end of season three when she donned Arsenal’s threads and joined Team Arrow. While we’ve only briefly glimpsed her fighting so far, Speedy (or Red Arrow) is likely to have her own central story arc to work through as she adjusts to a life of crimefighting in the aftermath of her return from the dead.
At the end of season three, Thea’s father Malcolm took over the League of Assassins, and while it’s unlikely he will be the central antagonist once more, his presence will certainly be felt at some point within season four, hopefully in a confrontation between him and his now costumed daughter. Combine this with Thea’s potential for some more crazy following her dip in the Lazarus Pit and it looks like Oliver’s sister could become the breakout star of season four.
Pray that the writers don’t kill Thea off just as she becomes more interesting, ‘Beth style’… You know exactly what I’m talking about.