This is the Prestige Class I am using
The Black Chains
The Black Chains are members of the city's thieves guild but operate as a self contained group. They seek to maintain the status quo of the city. The guild has learned any major disruption to the city's normal routine affects the guild, usually to its detriment. The Black Chains operate from a militant stance to control and guide any major upsets to the city. Plague, invasion or other events are addressed by the Black Chains. They travel outside the city and may join groups of adventurers and other organizations that one would not normally associate with the thieves guild but a Black Chain will still seek to control the group to their own ends ie the Guild's ends. Those in the guild recognize a Black Chain by their darkly colored spiked chains.
Since the Black Chains are a more militant arm of the thieves guild they sometimes act as shock troopers for the guild in keeping the guild strong and dealing with splinter thief guilds or those that do not "tow the line" for the guild. Members of the Guild are often trained/groomed for the Black Chains.
Most Black chains are trained fighters and rogues though some other classes can advance into this prestige class it is unusual.
Requirements
BAB : +7
Skills : Tumble 5 Ranks, Bluff 5 Ranks, Gather information 5 Ranks
Feats : Exotic Weapon (Spiked Chain), Weapon Focus (Spiked Chain), Expertise ; Improved Trip or Improved Disarm
Alignment: Any Non-Lawful
Other : +2d6 in sneak attack.
Class skills : Balance (Dex), Bluff (Cha), Climb (Str), Craft (Int), Escape Artist (Dex), Gather Information (Cha), Hide (Dex), Innuendo (Cha), Jump (Str), Listen (Wis), Move Silent (Dex), Profession (Int), Search (Int), Spot (Wis), Tumble (Dex)
Skill Points : 6 + Int Modifier.
Hit Dice : 1d8
Starting Feats : May take Weapon Specialization with Spiked chain using a normal Feat.
Bab : As A Rogue
Hit Dice 1d8
Saves Good Reflex, Others poor
Abilities :
1 - Disarm & Trip bonus / Sneak Attack +1d6
2 - Climb Fighting / Challenged Tumble
3 - Extended Tumble / Improved Feint / D&Tb +2
4 - Sneak attack +2d6 / Double Chain
5 - Rogue Special Ability / D&Tb +3
6 - Canny Focus
7 - Sneak Attack +3d6 / Increased Critical / D&Tb +4
8 - Rogue Special Ability
9 - Improved Canny Focus / D&Tb +5
10 - Sneak Attack +4d6
Disarm & Trip Bonus - On Trip and Disarm attacks, when contesting against opponent gain a bonus equal to +1 for each odd level of Black Chain, So +1 at 1, 3, 5, 7, 9. This bonus only applies when using a Spiked Chain or Flexible weapon (chain).
Sneak Attack - Works as Rogue Sneak attack and stacks.
Climb Fighting - Suffers no penalties when climbing and fighting. Opponents gain no advantage. (Works as Master of Chains Climb fighting)
Challenged Tumble - When someone attempts to Tumble through an area threatened by the Black Chain they make a normal tumble roll but still suffer an attack of opportunity. If the Black chain can make one ie has not performed their limit this round or is not flat footed (though combat reflexes allows an attack in this case) etc. The Tumble roll or the normal AC, which ever is higher, is the AC the Black chain must hit during this attack of opportunity. (Example - A rogue tumbles around a Black Chain, he normally has an AC of 18 but rolls a Tumble check at 23. The Black Chain can roll to hit an AC of 23 even though this would normally be a successful tumble)
Extended Tumble - This allows the tumble movement to increase from 20 feet to 30 feet but cannot exceed the Black Chain's normal movement rate.
Improved Feint - Feinting using the Bluff skill becomes a Move equivalent action instead of a Standard action. (As per Gladiator)
Double Chain - The character can use their Spiked chain as a double weapon and gains the Ambidexterity and Two weapon feat when doing so. The threat range for the spiked chain drops to 5 feet when the weapon is used in this manner for that round.
Rogue Special ability - The Black chain may choose one of the Rogue Special abilities normally gained by a 10th level Rogue.
Canny Focus - By focusing their mind on a single pursuit/task the Black chain can add their Intelligence modifier to a Saving throw, Skill, Base attack, Armor class or Stat check as a circumstance bonus. Used as a free action and lasting a round ( or perhaps more than a round for some skill use at the GM's discretion ie for skills requiring more than one round (such as disable device) to be reasonably executed but seldom more than one roll in any case). It is usable once per level in Black Chain per day.
Increased Critical - Add 1 to the Critical Range of the Spiked chain, stacks with Improved critical.
Improved Canny Focus - May now apply the Bonus to two separate rolls in a round as a Free action and number of uses per day increases by 3 Plus positive Wis modifier (Reflecting the will power required to focus on a task)
Hope this is of interest if not sorry for the wasted space.