Here is an old guide from a earlier issue https://web.archive.org/web/20120905073510/http://boards.cityofheroes.com/showthread.php?t=115071 but a lot of the concepts still hold true.
Some quick notes:
Gloom & Moonbeam do huge damage and you have skipped it, you need them
Tenebrous Tentacles while kind of a damage ability should be treated as a hold with damage and not a damage ability with a hold.
Hasten is nearly impossible for a Dark/Dark Corrupter to use because of the huge endurance drain of your powers & your main powers quickly cycle in a chain anyway
Dark Pit is probably one of the worst powers or was, I see zero need for it in any build.
Fearsome Stare is your most powerful ability needs more slots devoted to it
Also, it appears to me that for whatever reason Dark powers miss more than my other characters powers, for that reason I would not be afraid two slot accuracy when in doubt
Dark really requires you to follow a progression, Control is key, if you lose control, your damage abilities can't save you
Hope this helps