Saw Overwinder and had to make this. It is slightly different than some of the other ones floating around out there. Mainly, instead of Calderan Gunsmith as a secondary finisher, I have a Kalis. Also, I run 4 Amethyst Waystones, 2 Extinguishes, and 2 Grasping at Shadows.
Nightfall is great in this deck. You want them drawing more b/c of the Manacles. Also, you can get more grenadins.
Also, since you deck yourself, having the Grasp at Shadows is awesome.