Here is another Deceiver, with a bit higher casting speed. If you want to use Oblivion effectively, you’ll want cs. Harbinger set makes it hard to get above 170 with reasonable cc and defense. 
(even with max-roll cs on the gear).
Chaos Harbinger DB/Oblivion Deceiver
I left the green and conduit suffix blank, in the case you are self-found. Also, spirit is cranked, but you don’t really need it that min-max.
Likely for an optimal Oblivion/DB build, a different 2H/gloves with cs would be preferable to get up to 200% cs. It’s not like Harbinger really needs a filler…you shoot stuff.