Meh, EmeraldTiger asked me to do a full view into this thing.
Darkness' Physical properties:
Absence
Disablement of Sight
Span of Nonexistence in any celestial body
The plane on which the universe lies (Void, though BloodShadow would argue that the Void and Darkness are 2 separate things, I disagree)
Darkness' Ideological properties:
Inherent selfishness; The need to look out for oneself given almost all circumstances
Manipulation; The ability to use resources as a counterweight to benefit oneself while causing the person opposing to deteriorate in strength
MY interpretation:
Darkness represents balance. As it is, in purest form, nonexistence (The properties of Absence having no physical form), and this universe lies on a plane of nonexistence (if you took the universe out, there would just be a Void, "filled" with Darkness).
Darkness is balance because no matter what, Darkness in physical form cannot overwhelm substance. It merely is a placeholder when substance is absent.
Any other additions you guys want?