I need some story advice. In the Edge of the Empire campaign that I'm running my crew adopted an npc street urchin (roughly 12 years old). During our last session, the crew fought a pack of corrupted ice wolves (a pack of ice wolves heavily corrupted by a dark force user). The defeated the wolves and our intrepid pilot cut out a tooth from the pack leader and turned the fang into a necklace that he gave to urchin. It was very touching and I immediately thought, "Wow! That would be such a great way to turn this loveable sweet child into a devious and psychotic killer." My thought being, that this necklace would gradually cause a personality shift by magnifying the negative impulses in the child and if the crew doesn't catch it in time, ultimately destroy the character. Is the idea of the dark side of the force clinging to the fang and slowly corrupting an innocent too far out there?
If not, what would be some subtle ways to show the shifting of her character? I was thinking having her start playing some malicious practical jokes on the crew, temper tantrums when she doesn't get her way, and as she gets further and further towards the dark side attacking innocent people who cross her. Any other ideas or scenarios?