A character idea, but need to stop it being cliche. Any ideas?

[Cheka Man]

A wood elf girl, captured by dark elves and seemingly destined for slavery and death, was saved because of her resemblece by chance to a dark elf girl who had recently died. The family adopted her on a *trial* basis. She learned all she could about the dark elven girl and willingly adopted her ways, and prospered more then she would have done as a wood elf. Now years later few traces of her former self remain, to the point where she would happily raid her own village.

[Kuseru Satsujin]

The only thing that really comes to mind is perhaps also as cliche. Have the two girls willingly switch places, instead of having the dark elf girl having died.

[Cheka Man]

Interesting. *wonders  how a dark elven girl would do topside*

[Maggot]

The adoption of the wood elven girl could be part of some scheme by the dark elves to create an agent that could infiltrate the society of their foes. The dark elven girl, for her part, could be a spy trained to snoop on her adoptive culture.

[EchoMirage]

I would not make the evil transition so complete.
She might appear completely changed on the outside; what rests in her heart few can say.
Give her family an important position which the girl is to inherit, and suddenly it becomes more interesting.

[Kassy]

I wonder how well the dark elven firl woud fit in with the wodd elves, if the two had switched places, not as well as the wood elf with the dark elves, i'd imagine.