help making a BBEG 3.5

[Drackstin]

im a new DM and i have a few ideas i want to mess around with, my group is just leaving a big city, and i want to have a minor BBEG for them to have looking over there shoulders. im trying to make it scary for the group, so im taking some pointers from heros of horror.

Description:
he will be very thin and lengthy: so any race that fits that will be good

he will have a rogue type build: i want him to fade in and out of shadows right in front of the party.

i would like him to have frightful presence.

he will most likely be in all black leather straps for armor. and be able to contort his body.

he always wears a round white mask with a giant smile on it

one of his eyes is grafted.

other then that he will be hunting down one of the party members, but has been gathering information on the the hole time, so he will pull out all the things that no one knows about them.

he will also be leaving trails of blood that say "i know" for the group to find.

so what im really looking for is a race and a few classes and feats to make him like this, any suggestions?

[Emperor Tippy]

What ECL and what optimization level? Oh yes, and any class preferences or the like?

[Drackstin]

What ECL and what optimization level? Oh yes, and any class preferences or the like?

i would like the build up to 10th level but he would be 6th or 7th when they first meet him.

as for class, something that has shadow step or pass threw walls, his is going to be like an "assassin" but maybe not the class itself

[Biffoniacus_Furiou]

Dark Creature template from Tome of Magic for fading in and out of the shadows.

Feats Aberration Blood (Flexible Limbs) and Inhuman Reach from Lords of Madness for making him a thin contortionist. Also check out Darkstalker while you're in that book.

You can put those on just about any humanoid race.

The Fear Handbook (http://brilliantgameologists.com/boards/index.php?topic=3809.0) for how to be mechanically scary. The feat Dreadful Wrath in Player's Guide to Faerun is probably the easiest and most effective frightful presence for creatures with class levels.

[Skud]

He sounds a bit like Slender Man

[Nettlekid]

Consider just using the monster Murderjack (http://www.wizards.com/default.asp?x=dnd/fw/20040828a), perhaps granting it the Swordsage's Shadow X maneuvers and scaling down its HD to better fit the party's level? It has a lot of what you want already.

[KevlarTheD]

Duskblade always struck me as a cool class, with a martial focus but a definite magical twist.
I'm not sure their spell list matches up exactly with what you're thinking, but it should be close enough. I find self-buffs work well for making an evil villain terrifying in initial encounters without actually over-endowing them. Later on, the party can realize part of their fear was based in ignorance (fits with the shadow theme of the villain) and realize that a few de-buffs can go a long way towards making the villain less scary in both a mechanical and psychological fashion.

Nale from OOTS would also be a fair inspiration - obviously you're going for a darker character (literally and metaphorically), but rogue/fighter/sorcerer gives a LOT of character building options.

Another thing to think about is age - are they veteran bad guys, or is this their first "official" evil plot?

A quick idea based off those thoughts:
1. go Rogue at first level. This nets you a crapload of skill points (you don't want your big bad guy to be failing his Spot and Balance checks all the time) and could represent the villain's rough upbringing on the streets as an orphaned street child.
2. Their second level or two would be fighter. This is when they got a little older, and began to bully other street kids. By the time he was a young adult, the villain was as tough and nasty a street fighter as any. This will also net your character some respectable HDs - you can't have a recurring villain that dies in two hits.
3. Sorcerer or Duskblade from that point on. At some point in his young adult life, *something* happens. This awakens his internal magical abilities as a sorcerer, duskblade, etc. This could also be something tragic, which sets them on the course of true evil villainy, explains the motivation for the mask, or both. Maybe he was showing off his new-found powers and accidentally killed his only friend, and/or horribly scarred his own face/lost his eye in the process?

Some thoughts. Hope this helps or inspires!