>Warders: Kill defilers, protect the wilds,
>etc.
>Entropy: Be chaotic.
>Dawn: Save stuff.
>Maran: Kill evil stuff.
>Warlock: Kill evil magic stuff.
>Arbiter: Protect newbies in cities.
>Battle: Be tactical, kill magic.
>Scarab: Free your will and everyone
>else's.
>Scion: Bring.. uh.. eternal.. night.

For the sake of argument, can we extend the one-line summations to include Scion?

Scion: Kill wealthy stuff. Gather wealth and exert power over all others.

I am basing this on the helpfile:

"a group of black-hearted souls whose PURSUIT OF POWER"

"Driven by pursuits of SORCERY, DECEPTION, or MANIPULATION, they are all reflective of the dark and twisted nature of the Eternal Night. They BOW TO NO MASTER and FEAR NO DEED THAT WILL GET THEM TO THEIR GOALS (pursuits of sorcery and power). The power of the Scions resides with their wizards."

I capitalized the parts that seemed particularly clear in directing me toward the Scion goals. The goals are defined as:

1. Pursuit of Power. (Wealth, over other individuals, over other cabals, over nations). This can fall under "kill good stuff, gather wealth and exert power over others."

2. Pursuit of Magics and Sorcery. Like the old Masters, Scions should be the greatest and most knowledgable mages in the game. Nothing should remain a secret to them for long.

Now whether these are interesting goals or not, I can't answer, but they seem as directed as any of the others that you listed. It's kind of up to the players to live up to them and bring power and wealth to the Chasm.