Urban Ranger may be a good fit! A kobold urban detective with a dire weasel... I like that.
Any organisations that may be candidates for the Favored Enemy feature, in that case?
Well, there are two groups of cutthroats/thugs that ply the streets and canals of Sordadon: the
Golden Sabres and
Hammers. However, they have less influence in Bluffside proper due to the local thieves guild, which has a stranglehold on the rest of Bluffside's vices. The name of the guild is kept quiet to the fear of reprisals, but most locals know what it is called:
Who runs the guild is a complete mystery, however.
During the recent disaster in New City, the thieves' guild seems to be simmering quietly underneath society, waiting for things to get back to normal. The presence of the Bluffside Regulars and their second tier, the Bluffside Elites, has been heightened, so thieving and running protection rackets is tougher across the city right now (nearly impossible in New City, which is under martial law).
(FYI, think of the Regulars are your standard city guard and the Elites as musketeers.)
Another possible candidate is a group known as the
Rising Swords. They played a part in the New City disaster and are an infamous group of mercenaries who are vicious and cruel. After the previous PCs uncovered one of the group's hideouts in the Undercity, most of their members have either slipped out of the city or gone into hiding. At least, that's the thought by the leaders of the Bluffside Regulars.
There is a group that work for the renegade sorcerer known as the
Loyalists. They are completely loyal to Phelix Del Cannitha and none of them have ever been captured alive. They are fanatical and do not surrender and will even commit suicide to avoid capture. While it is known that Phelix comes from the city of Sharn far to the south, most of the Loyalists encountered by the previous PCs seemed to be local recruits.
You are
very likely to come up against more members of the Loyalists since tracking and defeating their master is one of the key goals of the story. I'd say the Rising Swords would be next on the list, closely followed by the thieves guild.
Finally, you could also consider making members of
House Del Cannitha* a favored enemy, but since Phelix is a pariah who was cast out of his house, you aren't likely to face other members of that Dragmonmarked House in Bluffside (unless they are also outcasts).
Note also that the ruins of Sem La Vah hold a lot of dangerous creatures (mainly at night) including vermin and the undead (mindless more than intelligent).
Once you have your PC more fleshed out with skills, you can roll to see if you know more about the clandestine groups in and around the city.
DM's Note: * Each of the standard Dragonmarked Houses from the Eberron CS have an altered name and background for my world. House Del Cannitha is the main one I've renamed, so far.