Thieves use the weaknesses of others, like greed and vanity, to trick them and to steal from. They often do this purely for the necessity of survival and as a challenge, too. It is their way of living and their skill. Seeing how the Thieves Guild has got their own treasure vault and collection of trophies do these thieves have a few low motives of their own, motives usually found only among the richest. It makes them appear greedy and vain.
They then get cleaned out by one of their own kind, and well deserved, is what I thought. Not that I liked Mercer killing one of his own people, no, but emptying the treasure vault is such a classic thief's move. I wished I could have turned on Karliah and Brynolf, too, split the loot with Mercer and then go my own way. I felt more respect for Mercer than for any other member of the Thieves Guild.
How did the Thieves Guild become so tough and weak at the same time? It did not make much sense to me. It almost seems like they deserve to live in the sewers and having their pants pulled down. It certainly explains why their time of glory lies in the past and no one but you can become their new leader.
Mercer was the only thief who I felt most connected to, being a bold and cunning thief, while the rest are not more than whiny thugs with glaring eyes. I am left with the desire to kill all the remaining thieves and to lick Nocturnal's feet three times a day.

