Interesting Drow "Assassin" builds?

[Scarey Nerd]

My players took out a group of 4 Drow Warriors with such unbelievable ease (Mainly because I misunderstood the albeit already poor CR system), I want their experience to feel like it had some sort of consequence. Therefore, they now essentially have a Drow bounty on their head for killing them. I'm trying to think of an interesting build for a LE Drow without having to look at the Assassin prestige. The 6 players are currently all ECL 4, though I'm thinking this guy won't show up till they're level 7 or 8. At my estimation, that would suggest about a level 9/10 Drow, probably with Ranger as the starting class and branching out into something lethal (Justiciar was my first thought, but their class features tend to bolster non-lethal damage which isn't much good to me).

For reference, the party is mostly low Tier: A Ranger 1/Fighter 3; Ranger 4; Fighter 4; Cleric 4; Scout 3; Swashbuckler 4.

[Particle_Man]

Maybe swordsage, with some shadow, diamond and tiger stuff in there? If the party is going to kill (or be evaded by) the assassin in 4 rounds anyhow then you don't have to worry about their low refresh rate.

[Petrocorus]

For reference, the party is mostly low Tier: A Ranger 1/Fighter 3; Ranger 4; Fighter 4; Cleric 4; Scout 3; Swashbuckler 4.

Races?

No arcanist?

Given the party is mostly mundame with only 1 caster, an arcane caster would have a edge on them.
A Vigilant or Suel Arcanamach build can fit too.
Ebonmar Infiltrator (City) and Fatemaker (Planar) are similar to the Assassin. They allow different builds.
You can start the build with (Urban) Ranger 1 / (Lion Spirit Totem) Barbarian 1 / Fighter 2 / Paladin 2 / PrC 4 or (Urban) Ranger 1 / (Lion Spirit Totem) Barbarian 2 / (Sneak Attack) Fighter 1 / PrC 6

Another solution is to go psionic with Ranger 1 / PsyWar 9
Or to use the ToB. A Warblade or Swordsage build can perfectly fit the role. Keeping the First level as Ranger.

[Kazuel]

Make him a duel scimitar wielding maniac just to mess with them.

[Scarey Nerd]

Make him a duel scimitar wielding maniac just to mess with them.

And he shall be called... Itzirdz.

The pure Fighter is a Warforged and the Scout is an Uldra, the rest are all human. I should have mentioned that I don't use psionics, my bad.

[Particle_Man]

If you bump it up a few levels (to be actually challenging) you could go with Arcane Archer, because when else is anyone going to use that class?