Well, my alt lvl 75 mini and my friends 85 guard manage to duo DN with the exception of bringing an LM in to click the blue rock on that one boss. It was tricky for some fights, but alot of fun.
The blind one was especially fun. The last phase got crazy with the clones, corruptions, black holes, and root/-heal puddles. When it got down to 30k or so, it was complete madness. Such a blast.
We got to the mistress:
We hoped the mezzing mobs wouldn't spawn 3 with only 2 people in the instance. We weren't so lucky. (it was a long shot)