Help with character building?

My group is starting a new campaign and I'm looking to do something different than usual. However, as a fairly new Pathfinder player I'm not totally sure of what direction to take. So far it seems like we're going to be pitted against old PC's the GM has around, including a 20 summoner with an eidolon. (GM must be out to kill us. X])

As far as the other players go, I know the party will have a whirling dervish, a summoner (of some kind), an elemental knight, and a frontline fighter with a bit of range. Although I have a bit of a character built in my head, I'm concerned with filling in the gaps in the party.

We are starting with a 20 pt buy, as level 10s. I am very interested in playing a CE Drow sociopath. Obviously we are not wanting for melee characters here. I've been tipped off that at some point we will be pitted against each other and am very concerned with being able to hold my own during this eventuality. Concealable weapons and poisons make me very happy.

So, do you have any advice for optimal class choices? Builds? I'd like to try an utilize the Drow's natural abilities as much as possible. Ideally, this Drow would balance story with ability-to-survive against other well-rounded PCs.

Thanks for any help and any pointers, I very much appreciate it. I'm having a hard time settling on anything here. ><

Perhaps some way of staying hidden. Are you wanting the drow to play off his deception and cunning? If so I would look more towards roguish build. Is the whole group evil? Do you need to disguise yourself as different personas to stay ahead of the game? Deceit and cunning might be a fun way to go. If I was doing a Drow giving their background i would hide that I am a drow somehow using that as a ace up your sleeve. Get people to underestimate your character then when you turn on each other you have the advantage.

Just my 2 cents
Just ask if ya want some more ideas

Perhaps some way of staying hidden. Are you wanting the drow to play off his deception and cunning? If so I would look more towards roguish build. Is the whole group evil? Do you need to disguise yourself as different personas to stay ahead of the game? Deceit and cunning might be a fun way to go. If I was doing a Drow giving their background i would hide that I am a drow somehow using that as a ace up your sleeve. Get people to underestimate your character then when you turn on each other you have the advantage.

Just my 2 cents
Just ask if ya want some more ideas

The party is going to be made up of evil/neutral builds, I believe. As far as character, exactly so. I'm definitely interested in keeping everyone else on their toes in regards to just what I am capable of. Do you have any recommendations for a good disguise? Starting at 10, I've got some wealth to throw around as far as items are concerned.

So, a rogue/ninja base would be a good idea. I think in the advanced race guide drow get some sort of class bonus for going rogue. Do you think it would be worth it to head for a prestige class? I've never tried that either. How could I maximize my damage dealing, besides sneak attack?

Thanks for the help. :)

Look over stuff that will enable you to take various personas with easy then. Disguise wise I would select a few you could pull off with your skill base. Perhaps your a bard traveling around. Or even a Alchemist that doesnt specializes in bombs but poisons. Fighter of sorts. I dont think u could pull off a wizard or sorcerer mimic. If you have different personas and kept them always thinking you weak then you will have a good turn. Some of the rogue alchemist builds are interesting or perhaps a rogue bard. If deceit is your way than bard might give you some illusions to boost your disguise. Think how superman played out as clark was always a clucks and tripping over his own feet. You could be someone that just doesn't get things right at the first. Bluff and Disguise will be your best friends as well as being able to say slide poisons in drinks and such when they are not looking. You could come off as a cook as well. Some meals are good and some well it would be the Last Supper.

You have to decide what is your primary goal, filling in the gaps in the group or surviving the PVP to come. Trying to fill the gaps will make you weak and easy prey. Focusing entirely on your survival will be good for the PVP area, but the group will suffer for it.

I don't forsee this campaign lasting very long, evil campaigns rarely do. If I were in your place, I would go for a druid. They can fill some of the gaps and wild shape means you are never without weapons and can readily escape if a fight is going against you.

Drow Drood could be interesting and like Siey said you would have Wild Shape to back you up. Mix that in with Disguise and bluff that would give you a interesting concept. You could use a wild shape to maybe spy on everyone. I was also thinking if you could look like another player you could later get them to kill each other before focusing on you.