Here's what I'm looking for...
Someone who is tops at stalking and hiding (obviously), someone who can scale walls, and is extremely nimble and quick (climing, acrobatics, and tumbling, I suppose). But, if I were to follow the idea of the character from the game, he's also somewhat of a social character able to make allies and gather information through contacts. So a good Presence is a bonus as well as some social skills. Diplomacy, I guess?
His weapons of choice would most likely be daggers/knives, a short sword, and maybe a small crossbow (for ranged kills). I also see him as being a skilled martial artist.
Skills in creating poisons would be cool as well. I'll have to look...is there an Alchemy skil? For some reason I can't remember.
Anyway, it's a tall order for a first level character, but he'd be neat nonetheless.