In that case you can still make the build work at those high levels
Your build would go something like Whisper Gnome Dark creature LA+1/rogue 3/fighter 2/monk 2/Blade Bravo 10
Take all the flaws you can. You want
Combat Expertise, Dodge+Titan Fighting (RoS); WF(rapier) [prereq], Weapon finesse [prereq], Underfoot combat, Confound the Big Folk, Craven, Darkstalker, Dragonfire strike (DMagic), Staggering strike (CAdv) and the TWF line. The Mage slayer line and Elusive Target (CW) are also good
Take the Cosmopolitan Feat to get Iaijutsu Focus skill (Oriental Adventures) always in class and max it. Use a gnome quickrazor (RoS)
Also make sure that you take the Penetrating Strike ACF from Dungeonscape, the Spell Reflection ACF from CM and the Hit and Run tactics ACF from Drow of the Underdark
Appreciate the feedback ShubNiggurath. I can understand the Dark template, the Rogue w/ ACF from Dungeonscape, the Fighter w/ DotU ACF as well as the assorted feats initially listed.
Cosmopolitan Feat isn't allowed (Oriental Adventures is a 3.0 book)
Spell Reflection ACF from CM is nice, but you suggested Monk 2 in place of Conjurer Wizard 1/Swashbuckler 1. Is the reason you suggested Monk 2, to get Evasion back? Therefore, the build would be Rogue 3/Fighter 2/Monk 2/Conjurer Wizard 1/Swashbuckler 1/Blade Bravo 10/Add your flavor 1?
What you have given me so far is extremely useful. I will be utilizing this build as it fits the ticket perfectly. I'm mostly concerned for optimization purposes on your suggestion there
Cosmopolitan is FRCS, Iaijutsu is OA. Without Iaijutsu you lose some punch but you you still kick ass
I have proposed an ECL 18 build (remember LA+1). You can top it off with conj wizard 1/swashbuckler 1 for sure, but I would much rather continue rogue to get uncanny dodge and +1d6 SA.
The wizard level is nice though, if you don't use multiclass penalties I would take that early instead of fighter 2 (simple wizard variant for fighter bonus feats). Monk 2 is a nice level (bonus feat, evasion->spell reflection, +1BAB, +1/1/1 saves, better flurry) so I would keep it especially if you can't use iaijutsu (and therefore will use unarmed strikes to fight to get an extra attack from flurry). Go cobra strike monk (you need dodge anyway and mobility does not hurt)
If you are finding that you can't squeeze all the feats in you could go LA+1/rogue 3/fighter 1/conj wizard 1/monk (cobra strike) 1/swashbuckler 1/Blade Bravo 10/rogue +2
But I like more (for the reasons above)
LA+1/rogue 3/fighter 1/conj wizard 1/monk (cobra strike) 2/Blade Bravo 10/rogue +2
And if multiclass penalties are enforced:
LA+1/rogue 3/fighter 2/monk (cobra strike) 2/Blade Bravo 10/rogue +2
(as I have proposed above)
Note that there is a bracer on the MIC that gives you a feat in the TWF line. Also BB gives free feats and the only decent choices are the TWF line again, so don't use your standard feats for those
Note also that if you DO take that wizard level you will need to spend a bit extra money for thistledown padding (RotW) to avoid ASF (you should already be wearing mithril anyway). Remember the Greater Blurring on the armor. Get a (darkwood) shield as well.
Finally, this build does not need invisibility. You are always hidden and therefore effectively invisible at all times, as long as you are not fighting someone with a huge spot