Howdy!
I'm kind of a noob here at the Assassin forum, but I DO have a suggestion you might try. It's definitely PvM (me not having great skill or inclination with PvP), so if that's not your thing, just skip this post:
Mentalist (Haven't come up with a better name, sorry.)
Main attacks: Psychic Hammer and Mind Blast
Enablers: Cloak of Shadows, Venom
Backup Enabler: Fade
No twinking, live off the land (no buying weapons/armor in town), no shadows.
I am currently working with this build in Hardcore. Granted, I'm testing her SP, and if you decide to test your character in HC mode as well, I would recommend that route rather highly--lest lag take her before her time. Tenatively, I have not allowed my girl any traps, though I might, at some point--it's doubtful, though.
Whatever you decide to do, good luck.