If the Dark One was around.....

[Thalia]

Mwahahaha! Interesting question.

Soren would for sure end up Forsaken, as a trade off for knowledge. No cost too high.

Oriena would also probably end up on the "dark side", just by her associations and general attitude.

I think the rest would stay with the Light. Though having said that, Thalia could probably go either way, depending on what people she surrounded herself with.