I like it. I'd definitely read the back of the book, and read the whole first chapter to give it a fair chance to hook me into the story. Personally, I think what it really comes down to is how much time and effort you'll put into making the story work. And by "work" I mean work out plot holes, bad personalities, awkward phrasing, pretty much anything that kills immersion. I'll list my own nitpicks, but I don't want to discourage you. You're the writer after all, not me.
Heh. Discouragement is sorta what this thread is for; to find out which audience I'm hitting. Am I going for the younger, average person, or a more mature, advanced reader? Thus far it looks like the former. Of course, I'm not exactly doing a great job of describing it, but I've stated my reasons for that and they can't be helped.
1. Don't even hint at anyone being a Mary Sue. Simply give them good personalities and move on Don't rely on psychological problems. Problems do not equal personalities. HOW a person approaches and solves a problem defines their personality.
I know. And this is something I don't have a reason for not describing properly, besides I screwed up.
Each kid has a very vibrant personality, usually relating back to their element. For example, the Air elemental is sort of flighty and air-headed, but she's accepting of her situation and finds it easy to mold herself to a new situation. Her boyfriend, on the other hand, is brash and hot-blooded, while being a total casanova and not entirely faithful. Said adaptation means Airhead gets somewhat Tsundre to keep asanova in line, which conflicts with the other girls, who were never trying for him in the first place ('cause he's a douche), especially since one is not only a devout, faithful girl but also a closeted homosexual.
Another is almost robotic, ever so slightly sadistic, and snarky. Since he's not only the most useless and has the most minor flaws but is also likely to get under everyones skin, he's the first to be offed in the name of plot. His main reason is to kickstart the storyline and then be a sacrifice to show off just how evil the villianess is. Much like the nice, adorable Spirit Elemental, his main job is to be a catalyst to drive the tension forward, and his personality reflects that. He's highly analytical to the point where it wouldn't be unexpected for a few of his xanatos gambits to keep moving well into the future, but since he didn't plan his own death into most of them, they start to fall apart and do things he didn't mean for them to do. He's also the one who contacted them all in the first place and brought them together, an issue I was having trouble with in the early stages.
The Villianess deserves special mention; I've been working on her for longer than any of the other characters.
She's obsessed with theater and puppetry. And I mean really obsessed, especially after her parents died. She was so distraught, she took their corpses and made them into gigantic dolls so that she could trick her little sister into thinking that they were just sleeping. It obviously doesn't work, because Sister is smart enough to notice her parents aren't breathing, but the whole family was so tight-knit she doesn't want to say anything unless she breaks her older sister even more.
Villianess, after slowly driving herself to belive her mother and father really are alive, starts to kidnap other people and taxidermy them. She begins to think of it as a way of making them immortal. This goes on for several years.
Eventually, she gets the power over Darkness, which not only manipulates shadow (rather weak and energy consuming; really only good for hiding) but can summon eldritch beings, not quite cthulhu but certainly his grandchildren. Dark also encompasses lies, and makes her very seductive to anyone unprepared for it. Mostly, though, she uses her powers as a very gory tool to disembowl and drag corpses back to her home, where she makes puppets out of them.
Dark grows in power the fastest, so while the other elementals combined might be able to finish her off, none can individually, save for water and earth, who each have their own reasons for not taking her out (unshakable pacifism and inability to work himself up into a rage, respectively). It isn't until the end of the book that the others are capable of working together, and by that time they're too weakened to do more than disable her. That's when Sister shows herself. Through the whole story we get to see Sister's love for Villianess drain away, and now all thats left is a haunted, angry shell of a five year old girl with unimaginable power. She'd left her childhood far behind her, and unflinchingly reduces her own sister to bone. When Villianess still refuses to die, filling herself with one of her eldritch beings, Sister takes her three years into the future and tells the other elementals that they have that much time to get their shit together and get ready to bring her down. She also warns that Villianess has only gotten more powerful, and that they won't recive help next time; indeed, she promises each and every one of them will die by her hand.
The main issue with takeing Villianess down isn't her power; or the fact that they don't even know what's going on (although that's a big part). The issue here is that the group have serious issues they need to work out before any serious teamwork gets done, especially now that they have superpowers. It only exaggerates their personalities, along with their issues. The Airhead, especially, has a group-effecting issue; she can't function without her medicine, and she runs out halfway through. She grows more and more paranoid, and eventually has to resort to some very unconventional and very dangerous procedures simply to be able to function.
2. Seven teenagers among the ages of "18,17,16,16,15,14,14" is going to have a lot of interpersonal drama. Are they working together? Do they like each other? Do they have crushes on each other? Do they share certain interests? Not all of them can be mature, how many (if any) will see past the ensuing drama? How do the 14s deal with the 18? Do they worship him/her, or distrust them for being an adult? All of these kids will still be heavily influenced by their parents. Is one of them gay? Is one of them religious? You've pretty much struck a gold mine when it comes to possibilities here. But, you have to manage it all too, otherwise the story will lose credibility. Also, the characters simply aren't going to work as a cohesive group, even adults can't manage simple group projects in smaller numbers. Which is a plus. On one hand, they'll be trying to save the world from an overpowering evil, while trying to not wring each others necks.
Oh they'll have some issues. Not just the ones stated above (murdering psychopath and Casanova loverboy can really grind on people when mixed) but others related to their backstories and coming to terms with what they were. To be honest, they won't actually come fully to terms with who they
are. The lesbian stays in the closet, The Jackass remains a Jackass, the Slow Thinker doesn't speed up an inch, and the dead girl becomes really creepily into dead things and dying.
Damn this is a long post. I hope this is helping.
A set of seven teenagers (18,17,16,16,15,14,14) are given incredible power over "elemental forces"
Again, really? Couldn't we have seven elements having incredible powers over teenagers, so that these deity like figures must try to manipulate otherwise normal kids into cold blooded killers and use them as pawns in their sick game of chess?
... IDEA IS MINE! STAY OFF IT!!!
... I honestly like this idea better than OP's
...I honestly agree. But I don't think I could write that complicated of a story. Seven characters in this one, total. Everyone else is dead. The fifth-most important man in the story is a airport attendant in Russia. Everyone else is a main character or far away.