I got bored and started making a sorceress with the intent of using Orb as one of my main killing skills. I had a halfway decent orber a good while ago and loved it. I also end up running countess for some strange reason. I don't know why, I'm just constantly drawn to the countess runs.
Now, last ladder I had a light sorcie and she was pretty fun, but couldn't run Hell countess that well (Count's minions are light immune on Hell). Now, I did look at a Meteorb or something along those lines, but Countess is Cold and Fire immune in hell. So, I ended up with NM countess runs, and would occasionally toss in someone else while I was there.
What I'm thinking is a Lightning/Orb combo. Orb for the minions while Count is casting her firewalls, then lightning for countess when she is done.
Has anyone ever tried something like this yet? I'm thinking she might be fairly good at other MF spots as well. Fire Immunes are everywhere, and poison imm. are scarse, but I won't be worried about either of those. occasional light immunes on the way to bosses, but there is Orb for them. Then Mostly Cold immunes in A5, but lightning should work good enough. Personally, I have seen few (if any) Cold + Light immunes.