This is a Future Idea, something that I may Pick up Much Later... I am not stopping any of my stories. Love, your Ninja Overlord, Mika.
Kushina Uzumaki was a Master of Many things. Sealing, Swordplay, Taijutusu, Cooking, Sex. However there was one thing that surpassed all of that, her ability to fake it. Kushina was an unparralled Master at that. From the Moment she was dragged the Leaf, Kushina used this ability to craft a Seperate Personality, one that would survive the hellish Life she was forced to endure.
To Start, she pretened she liked and respected Mito, despite loathing the stupid cunt for forcing her to be the Jinchuuriki after tearing her away from her freinds and Family. She was able to take advantage of the Foolish women and Learn everything she could on Sealing and Various Other arts.
To Fool the Members of the Village into thinking she was loyal, Kushina pretend to Want to become the First Female Hokage when in truth she wanted to burn the village down and piss on the ashes. Still this was effective in hiding her intent from the world and even allowed her the ability to beat the shit out of those that insulted her or assaulted her. However the best part as that it allowed the world to think she was only good in Taijutsu had no self control, from the Truth.
Even during Cloud's pathetic attempt at Kidnapping her, Kushina faked it. At that age she was more skilled them Most Jonin and had sensed her kidnappers far before she entered her home. In truth she allowed them to kidnap her, deciding to escape them and run away once they left the Leaf. However she knew there was a chance they would fail, so she left the trail of her hair for other's to follow to make it seem as if she was trying to fight them. When that Idiot Minato defeated her attackers, Kushina decided to take advantage of his obsession with her and mate with him so that she could produce a Powerful child and keep her eye on Minato who was dangerously Loyal to the Village.
Once she was Pregnant, Kushina again Faked it. She knew moments after conception that she was pregnant due to a Seal she made, however she hid her pregnancy for a few months. She knew that there was a very good chance that something would go wrong with her Seal or that she would be put down to ensure her child was loyal to the village and not to her. So, she spent three Months crafting a Seal that would implant part of her soul into her child and allow her to speak to him after death, even raise him from his own mind. She also went around the village in secret, creating Hideouts protected by powerful Seals and Genjutsu.
And So, once she actually gave Birth, and Obito Had Kyuubi ripped from her body and was sent to watch over Naruto as Minato fought the Kyuubi and their attacker, Kushina placed her seal on Naruto's tiny body, even sealing away her sword with it. She could feel her lifeforce fading... She would not survive this, but she would ensure that she raised her baby. She knew Minato would be foolish enough to seal Kyuubi into Naruto, outcasting him. So, she made it so that her Seal would feed on Kyuubi's Chakra, allowing her to manifest after a few months or even a Year.
What she never expected was for Minato to be stupid enough to use the Death Reaper Seal of all things to split Kyuubi up and place half into her son... that would complicate things, her seal wouldn't allow her to manifest until later... maybe three Years... or four...
Idea is that Kushina, My Dark Kushina, awakens when Naruto First Fails the Academy Test of sooner and takes to raising him. Teaching everything she knows, preparing him for Shinobi life and for Defeating Obito ( who she knew was her attacker as she could sense him).
Dark, Smart, Sarcastic Kushina. Powerful Naruto, Smart Naruto, Sarcastic and Dark-Grey Naruto. Not a forgiving Story...
Naruto either Leave's after Kushina instructs him or leaves when Kushina takes over. Or she possess his dead body after Sasuke Kill's him in the Valley of the End and takes revenge...
This Idea can also work for Lily Potter, Scroll Down to See that part.
Lily Potter was a Master at Many Things. Potions, Charms, Runes, Arithmacy, Herbology, Cooking, Sex and so many other things. However her greatest Skill was Faking it. She had done it her whole life, Starting with Faking that she caring her her cunt of a Sister Petunia.
When she met her Creepy Stalker Severus, She pretended as if she wasn't disgusted by his prejudiced and his creepy obssesion with her. Still he was useful in preparing her for the Biased bullshit of the Wizarding world and supplied her with several Books that she found interesting. Like Severus, she was well versed in Potions and the Dark Arts before she entered Hogwarts. Severus also helped her to forge the Kind hearted mask she desired.
Later, after Severus had done his part as was no longer of use to her, she dumped his ass using the Mudblood comment as an excuse. She got with James, despite loathing him and his worthless bigoted friends, for Protection against Dumbledore and Voldemort and to later have a powerful child. It also helped to shield her from many other beings and gave her a massive library to search through which came in handy when she learned she was pregnant.
She used her Incredible skills to forge a Spell that linked her soul to her son, making it so that when Voldemort attacked her, her magic and soul would create an Anti-Voldemort Magic to keep her baby safe while allowing her to live in her Son's body so she could raise him and keep hs mind free from the bigots in the Wizarding World. To facilitate this, she had several Houses magically protected and stocked with Food and books, this way she could raise her son away from the Prejudice.
However... she never counted on the Fact that a Shard of Voldemort's soul would latch itself onto her son and that her son would be placed with the Dursely's... waking the blood spells on her son...
Lily Raises Harry after she mets him, training him in everything she knows and getting him as skilled as an Auror by the Time he gets into Hogwarts... Getting Sirius, who she loathes but wants to use out of Azkaban.. and killing her own Sister for the abuse on her son...