Dark Control, from what I've seen, is very range friendly, requiring that you be in melee range for either allies or enemies almost not at all.
As such, range-friendly secondaries would likely go well with it. I'm thinking /Fire and /Energy will be the better choices here, with /Elec, /Psi, and /Thorn not too far behind. /Earth is probably the worst pairing, but even that shouldn't be too bad, considering that Dark/ doesn't force you to really play at range.
Let me never fall into the vulgar mistake of dreaming that I am persecuted whenever I am contradicted.
~Ralph Waldo Emerson
"I was just the one with the most unsolicited sombrero." - Traegus
It's still early beta, there's time for it to change.
If you wish your voice to be heard on possible modifications to Dark Assault the best place for that is in the feedback threads in the Beta section.
(For what it's worth, many people agree. Dark Assault as is, is pretty underwhelming.)
@Oathbound & @Oathbound Too
Hesitating between a Darkness Controller and Darkness Dominator.
Secondaries are what's going to cinch the decision.
I have little experience with Dominator secondaries, but Dark Assualt doesn't seem exciting.