It works best mainly as a dueling set. Rad/ is probably the best of options to give you -def to help your heal hit. Fire is very viable as well, solo was a beast on his. I am working on an elec dark still that should be pretty decent, but my laziness prevents me from pveing to much.
Duel me.
I will work on my sig pic more when I have time.
rad/*
fire/* is trash compared to either rad or sonic. if frozen viper can do it from his trailer, you can do it from your toilet.
fire dark does pretty well depends on who your fighting - darkest night is fun as is the res which is an auto hit stun and -5000% regen lol.
God i miss when ice blasting was good 
Question about procs.. kinda.
If I slotted a hold damage proc in Dark Servant, will that make it so any time it attacks it has a chance for that proc? or just anytime it does the hold? Or does it not work like that at all?
It only fires when you he uses the hold. In fact the set ios will only buff the powers that it uses. Like hold sets will only effect the hold but nothing else and accurate heals will only effect the heal. For this reason I actually only use hami-o on dark servant. Big thanks to a pve power gamer friend who helped me with this info.
Duel me.
I will work on my sig pic more when I have time.
Dang. woulda been nice if he had a chance to proc every so often :-P
EDIT: So if I slot a -tohit proc in him it will work for 3 or so of his powers?
Is dark miasma a viable option on a corruptor for PvP? I know its -def and -res are in tar patch... but it has a hold, a cage, a heal, -tohit and -dmg, -def and -res along with -jump and -speed (when they're on tar patch, not sure how that works in pvp now), a stealth toggle, and a pet.
I know cold is probably way better, but im wondering if something like fire/dark or rad/dark is viable with this set.
Sorry for posting so many "does this work" threads, but i don't feel too bad since i feel like the questions, guides, and builds forum hasn't had too many new threads this weekend.
edit: or even an energy/dark?