The potential of this is incredible. Imagine.
One teen, who has maybe a passing interest in music without the vocal chops to carry it, wakes up one day with perfect pitch and a voice like an angel's. They always stuck more to the background, yet they're suddenly assertive and independent, going out on their own doing who knows what, becoming unusually angry when people speak over them. They have a stagehand role in the school musical and yet their fingerprints are over everything; they're policing everyone from actors to crew on what to do, and strangely, people start to listen, and stranger still, they start to like it.
One teen is a bit of a gossip, someone who knows everything about everyone. But the highs and lows of stereotypical school drama are starting to bore them. They're no longer satisfied by sappy crushes and student-teacher arguments. They want to see fights. Blood. Maybe they instigate, telling a bully one thing, a cheerleader another, and watching sparks fly. They watch videos of plane crashes and mob fights and other horrible things - who even knows where they find them. They drink it all in like a wellspring they can't get enough of. You have to remind them to blink because they keep forgetting.
One teen starts chasing thrills. Jumping fences. Exploring abandoned buildings. It starts off ridiculous and then becomes dangerous. Soon they start dragging other people into it, people that come back with indescribable looks on their faces, even though they've only been gone an hour - or at least you think so. All the while, the teen is laughing, saying how fun it was, oh so much fun. They have an unusual knack for the time, able to tell you down to the millisecond no matter where you are. They can solve equations impossibly fast. They say things you can't wrap your head around.
One teen starts eating anything and everything they can find. At first this makes them sick, because they overindulge. But it doesn't make them stop. In fact, it only gets worse; they start eating things they really shouldn't. Pages from a book, unlabeled bottles. You think you see them rummaging in the trash a couple times. They can't verbalize how it tastes. They just want more. They overflow with energy too big for their body, barely capable of putting it to words. Once it's time for the senior dance, they watch the usual candidates battle for prom queen and lick their lips.
The last teen is...different. Difficult to read. Their changes are subtle. They pronounce words differently. Use strange nicknames. Talk down to you, like a child. Really, the scariest thing isn't what they're doing, but what they aren't. They're far too calm for what's happening around them. They see their closest friends warp into monsters and smile like it's the happiest thing in the world. They show up everywhere. They want to be everyone's friend. They want to be your friend. They ask what you want. They have a way of making it happen. You ask how. They smile wider.
Imagine being friends with someone and knowing their traits, their habits, their quirks like the back of your hand, and then suddenly those things are twisted into something unrecognizable and were they ever even your traits to begin with? Or someone else's? Were you ever really you or were you just a byproduct of something bigger than you?
COUGHS. Anyways. I think it's a really cool idea.