Light Elves
Faithful
The faithful firstborn of the wood and sun, keeping an older grace on the Elven Isle.
When the divine host broke into three, the fault line ran downward through all of creation. Each kind of being cracked along the same seam, faith against the Void, but each cracked differently, so that "light" and "dark" mean something new for every people. This is the first thing to understand about the peoples of the Sundered World: darkness is not one thing. A dark dwarf and a dark elf are not the same evil, or even the same kind.
The Elves: the sharpest division
The elves, firstborn of the mortal kinds, split cleanest and most completely. The light elves kept faith with the withdrawn gods and hold to an older grace on their island refuge. The dark elves did not merely stray; they gave themselves wholly to the Void, and are the truest mortal face of the Fallen, beautiful and merciless. Between the two there is no middle and no mercy.
The Dwarves: the shallow schism
The dwarves broke, but not so deep. The light dwarves remain steadfast keepers of the Smith, faithful to the god who made them. The dark dwarves turned to worship the Smith's stone giants instead, and became shifty and self-interested; but they are not Void-sworn. They are shady, not damned, and can be dealt with by anyone who watches their hands.
The Half-Elves: the deathless middle
Apart from the schism entirely stand the half-elves of the Lonely Isle, deathless and isolated. Belonging fully to no side, they have made a private religion of not choosing, and their deathlessness has curdled that reluctance into paralysis. They can watch an age end and never once make themselves step in.
Men: divided on every side at once
And then there are Men, most divided of all. Where the other kinds fell mostly one way or another, Men fall on every side at the same time. In the same failing kingdom you will find the Sky-King's law-knights, the cults the Fallen recruits, the withholding wizards, and the ranger holding the northern line. Men are not a people with a nature; they are the whole schism, running through one kind.
Dark Elves
Void-sworn
Void-creatures sworn to the ending of light, beautiful and merciless, the elven face of the Fallen.
Light Dwarves
Faithful
Steadfast keepers of the Smith, faithful to the god who made them of forge and stone.
Dark Dwarves
Shifty
Shifty cultists of the stone giants, self-interested and unreliable, but not Void-sworn. Shady, not damned.
Half-Elves
The Middle
The deathless middle, alone on their isle, who can watch an age end and never make themselves step in.
Men
Every side at once
Heirs of ruined kingdoms and the most divided kind, falling toward faith, law, the cults, and the Void all at once.
Read on
The gods these peoples fell toward or away from are set down in The Pantheon. How they organize themselves around the fading light is The Six Orders. What the Void makes of the fallen is The Corrupted.