Well, particularly my 2nd favorite character in Sky Diver is canonically a "man of many mysteries" - an enigma that doesn't necessarily need to be lying, but there's a bunch of stuff he's not outright telling, which - depending on how you look at it - can, however, be considered lying sometimes.
In non-spoilery terms, Shadedancer holds many secrets to himself or his closest allies. Most of them include a bunch of hidden knowledge about people and overall lore (as it befits most mentor characters) and his actual name.
As for very mild spoilers, which will explain the character more a few more chapters down the road
Despite of the role he is seemingly playing, Shadedancer is not one of the bad guys. It's the whole opposite, actually, and also quite the sad tale.
He does make questionable decisions and acts quite shady for sure, fully aware of which skeletons he has to put in his closet to reach his own goal, but he genuinely cares about the people around him. And that's the one thing that makes him act a certain way towards them. He tries to form bonds, be it for information or help for his cause, but does not want to get too close to people because he's fully aware of what happens to those who get too closely affiliated with him.
To sum it up a little, the man has witnessed a lot in his life prior to the events of the story currently playing out.
The whole scope of his backstory, which gets revealed here and there even after Part I, is also one that makes him the most complex character in the whole project, as the events of his life before meeting Josi all solidified the role he has to play in all of this to reach this very important goal.