Finally pulled the trigger!! Which Lens would you get next?

Went and pulled the trigger on the 5D3 after reading all the reviews and wanting to go FF for a couple of months. Coming from 7D which I am keeping for the reach and loving the 17-55mm f/2.8, 60mm f/2.8 macro and 10-22mm that I have for that lens.

I do have a bunch of lenses for the 5D3 like the 24-105mm f/4L, 85mm f/1.8, 70-200 f/2.8L ii, 100-400L and 50 f/1.8, Canon 1.4 ii extender and the Tokina 10-17 Fisheye.

I mainly am going to use this lens for portraits, scenery and night time. With that in mind any recommendations on a wide fast lens?