This OC is by -misshatake I hope you like it.
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NAME
Uchiha Aijin

Cute name

AGE
[ Pre - Naruto ] | 6 years old
[ Naruto ] | 12 - 13 years old
[ Shippuden ] | 16 - 17 years old
[ The Last ] | 19 years old
[ Boruto ] | 32 - n/a years old

The Naruto age group, nice

GENDER
Female

Cool

SEXUALITY
Pansexual 

Nice

FAMILY
[ Uchiha , Mikoto ] - Mother , deceased
[ Uchiha , Fugaku ] - Father , deceased
[ Uchiha , Itachi ] - Older brother , deceased later on in Part II
[ Uchiha , Sasuke ] - Younger twin brother , alive
[ Uchiha , Sakura ] -  Sister - in - law , alive
[ Uchiha , Sarada ] - Niece , alive
[ Hatake , Kakashi ] - Husband , alive
[ Uchiha , Sakumo ] - Oldest son , alive
[ Uchiha , Eizo ] - Middle son , alive
[ Uchiha , Sunako ] - Youngest daughter , alive

Thanks for the relations and life status of each member.

;;  Eizo and Sunako are twins , but Eizo is older

Ok

APPEARANCE

[ Pre - Naruto ]
At the age of 6 , Aijin has pale skin , wide onyx eyes and hair styled the same as Mikoto . She wears a sleeveless knee high navy blue dress with a yellow bow tied around her waist , the Uchiha clan crest on her back . A beige coloured hip pouch hangs around her waist every time she is at the academy . Bandages cover her legs from ankle to knee , and the girl wears navy shinobi sandals for shoes . After the massacre , a scar rested on the left curve of her waist from Itachi's kunai .

She looks nice and your skills with description is great, it makes it easy to imagine what she looks like. Also the scar is a great touch.

[ Naruto ]
At twelve , Aijin grew taller , standing at Sasukes height . She wears her hair in a high ponytail , it brushes just past her elbows , and when let down , it reaches her hips . Bangs frame her face and are pushed up by the Konoha head band which is tied around her forehead . Her eyes became a pot sharper . Aijin wears a sleeveless turtle neck blue crop top , but reveals no skin because of the bandages tied from waist to hip . Along with baggy black pants which are tucked into mid calf navy blue boots . Her ninja pouch is strapped around her thigh , and she also uses fingerless forest green gloves .

The way she changes in appearance is great.

[ Time Skip ]
Between the ages of 13 - 14 , Aijin changed her attire to stick out less . Keeping her hair and bangs down all the time . The length of her raven locks was shortened considerably , now barely brushing past mid arm . She wears a long sleeved kimono that ends mid thigh , held together by a pale yellow obi . Weapon pouches attached to each side of it . Aijin also wears spandex shorts underneath , which are visible only when she fights . The shoe wear she chose is the exact same as what she used to have when she was 6 , including the bandages .

This is great and the fact that she changed her close to blend in more as a ninja should is great.

[ Shippuden ]
Now , Aijin wears her hair in a low ponytail , and it ends at her elbows once again . Though her bangs are styled differently ; like her mother's . She wears a turtle neck body suit which ends as shorts at mid thigh , and the arms of which manifest into black gloves on both her hands , which were holstered by her middle fingers . And tight , black cloths acting as foot guards on both of her legs , which start midway up her shins down to her middle toes , each held by thin straps at the bottom arches of her feet . They are also more decorative in nature rather than serving as actual "guards" , leaving her practically barefoot . Above the body suit , Aijin wears a kimono top ( sort of ) , that ends just below her chest . Her shoulders are exposed ( but still clothed ) , but the sleeves continue from then on till her elbows . Ninja pouch tied around her right thigh .

This is really good and the guards are a nice touch.

[ The Last ]
Elbow length straight , raven hair , bangs styled just like Mikoto's . Fair skin along with sharp , onyx eyes . Undone jonin vest , with a long sleeved black turtle neck , the sleeves of which are rolled up half way , tucked into a pair of high waited baggy black shinobi pants , which are also tucked into knee high combat boots . Complimented by black fingerless gloves with the Konoha metal plate on both of them . Ninja pouch tied around her right thigh .

Oh so she cut her hair, cute. Her change as well is also good.

PERSONALITY
Aijin is a pretty chill girl , takes crap from no one and is next level sarcastic . The young Uchiha possesses a very sharp tongue , which often lands in lots of trouble . Although she can be rather snappy , pushy and most of all , extremely violent when annoyed / irrited or if put under pressure . Aijin has no idea how to express any positive emotions at all , so the female may come off as a bit of a tsundere in those sentimental moments . While Aijin can see all her weaknesses clear as day , and even learn to accept some of them , she doesn't like anyone mentioning them at all , and gets hella defensive . The ravenette tends to get rather cocky and arrogant in times of battle , but she isn't really known to be a humble girl so it didn't come as a shocker to anyone who knew her personally . The girl possessed rather dark humor , mixed in with occasional perverse jokes of her own .

This is really good when it comes to highlighting her flaws but the one problem that kinda go against each other is the fact that she's chill but also extremely violent. Now under pressure I can understand but being annoyed when violent comes off as a hot headed trait like when Sakura is angry or annoyed she becomes violent and she's a hot head. Now Naruto also has a angered and violent expression when mad or annoyed by Sasuke or when he gets made fun of. However people I think that are close to her personality is Shino, Sasuke, Shikamaru, Gaara, and Neji. All of them are chill people but they don't turn violent when annoyed, not even Gaara so I would re-look at that trait again for annoyed and irritated but under pressure is fine.

BATTLE
Aijin relies heavily on her clans doujutsu , the Sharingan . Which often leave her vulnerable to any attack when she is chakra deprived form the overusage of the kekkei genkai . Though the girl isn't known for her physical strength , she is fast and agile , has quick reflexes and is overall good with taijutsu if relying purely on timing and speed . Though brute strength definitely isn't her forte . Because of her large ampunt of chakra , Aijin's jutsu arsenal is undeniably big , relying mostly on fire , lightning and water most of the time . Genjutsu is another field she is considered good at , because of her doujutsu and personal skillset . Though it definitely isn't her main field . Aijin knows her way around the hiraishin , something taught to her personally by her team instructor , Shiranui Genma . Because even he doesn't possess pull knowledge over that jutsu , Aijin's space time technique is broken ; overall , incomplete . Body flicker is a lot easier , but as stated above , Aijin loves showing off .

This is very good and the fact that she focuses the most on the sharringan makes it believable that she can be the best sharringan user. Nice

STRENGTHS
Speed , taijutsu , ninjutsu , genjutsu .

Nice

WEAKNESSES
Stamina , physical strength , chakra control , couple of emotional triggers .

Great that the weaknesses out do the strengths.

CLAN
Uchiha clan

KEKKEI GENKAI
Sharingan
Magenkyo Sharingan
Eternal Magenkyo Sharingan
;;  Not all at once .  She received her Magenkyo a lot later than Sasuke .

Nice and the fact that you didn't out do sasuke is great.

RELATIONSHIP WITH CHARACTERS
[ Kakashi ]
Ends up marrying him . Their relationship is build on mutual understanding and comfort , since Kakashi could somewhat sympathise with Aijin after the death of Neji , a person she loved all her life . They don't jump into a relationship straight away , because first , their bond started off as one of a teacher and a student , but gradually progressed into something more . It was mostly Aijin who proposed weekly meetings at the training grounds . She needed a good sparring partner to blow off some steam . The Uchiha often ends up pouring out all her emotions , and Kakashi is a good listener . That's what she liked about him . It didn't take long for Aijin to fall , but being scared of losing someone again caused her to distance herself from the man . Which confused Kakashi greatly , since they were close to each other . Long story short , he drags her out of her apartment and beats her around the training field to show her that he's strong enough to at least outlive Naruto , that she had nothing to fear and that he'd stay with her . Aijin ends up crying like a baby and sleeping over . I guess their journey only continues from there on out  (;

Now this is really good but I do want you to know one thing. Taking into consideration that Aijin is Sasuke's twin and is 12 at the start of Naruto, now Kakshi is 27 at the start of Naruto so the age difference is 15 years and I don't know you're comfortable with that. I personally would make her older so the gap can at least be least than 10 years. Not saying you can't still do this but if you want my opinion than that's what it is. Even if she was Itachi's twin sister the age gap would be 9 years but again you do what you want.

[ Itachi ]
Now , Aijin and Itachi shared a very complex bond . As you know , the older Uchiha had to keep up the act of hate ; to motivate Aijin and Sasuke to despise his very being and want him dead . Because Aijin knew the truth , every time he looked at her with an emotionless and dead gaze , her heart broke every time . They shared only one emotional scene , a while before his death , where they shared one last embrace . Itachi was low-key suicidal because of all the shit that happened in his life , and perhaps Aijin only did worse when she confronted him about knowing the truth . Only Itachi knew the truth and what he was feeling at the time , and the man took it to the grave with him . Aijin was devastated after the death of her older brother , causing her to fall into an endless pit of darkness . She couldn't see anymore , if that makes any sense whatsoever .

It makes sense I get it.

[ Sasuke ]
They have come a long way , that's for sure . After the massacre , Sasuke and Aijin distanced greatly , but still deeply cared about each other because no matter what , They were a family . Though Sasuke was so engulfed in hate and revenge , it concerned Aijin . She hated Itachi , too , but had different plans in mind . While she was forced out of the village , He left by his own choice , and it perplexed the female even more . Aijin saw his powerhungry nature , and now that she knew the truth about Itachi , She had to tell him . Though nothing was as easy as it first seems to be , am i right ? At one point , Sasuke is willing to take Aijin's life to unlock the Magenkyo Sharingan , since he's gotten that far . He had this idea in mind that was beyond Aijin , and it took a long time for her to forgive her brother . The death of Itachi only brings more conflict between the siblings , but in the end ( Boruto lmao ) , everything is well .

This relationship is so believable between her and Sasuke it's scary. If Sasuke ever had a sister and she lived as well I always thought this would be their relationship. Amazing.

[ Her Team ]
Genma , Shurui and Eiji . Someone she could never forget , even if she wanted to . They were all placed in one team purely by Hokage's mistake , but stuck and worked together like glue . Conflicts sighing the team only brought them closer , and Aijin was devastated to find out that she wouldn't be able to at least bid her goodbyes when leaving the village on Tsunade's orders . Even away , she considered them as family , and admitted to herself that yes , they have , in fact , greatly grown on her . How they reunited wasn't the best , but Aijin was relieved that now they were aware that no , she , in fact , wasn't dead but very well alive and  ( thriving lmao ) not thriving .

Great and the way she thinks I'd them is good as well

;;  i mentioned only the most important people 

Ok

OTHER
Aijin has plenty of mental issues .
It really isn't a surprise , because with what she and Sasuke have been through , it was almost expected . Nothing too severe , though .PAST 
During the massacre , Aijin returned home first , and after discovering most if her clansmen laying in a pool of their own blood , she hurried home . Where she found her older brother hovering over two unmovong bodies . Confusion , fright and anger followed , and long story short , by narrowly missing his sister with a kunai , Itachi left a scar on the left curve of her waist . Aijin was trapped in a frightening genjutsu , in which , from her older brothers point of view , she murdered everyone in cold blood , including her friends , parents , Sasuke , and weirdly , herself , over and over again . Sasuke himself arrived a while later . During those events , Aijin unlocked the first stage of her sharingan , though is unaware of the fact . She will start off by using her second stage in Part I , at the age of 12 .

Great and the fact that she has a mental problem is also a nice change. You show how she was affected by the massacre, great job.

After the death of her parents , obviously both Sasuke and Aijin were taken to a therapist , Yamanaka Inoichi . There were changes , but the damage was already done , sadly . 
After Itachi defected , Aijin officially became her clan's heiress , because she was slightly older than her twin .
With that came a lot of responsibility , and it only got more difficult from there .

And while Aijin's personality was quite difficult for anyone to put up with , a certain Haruno was set on befriending her , though failed because the ravenette possessed a sharp tongue.

A while after the Chūnin exams , Yakushi Kabuto arrived to inform the female Uchiha about her older brother , how he loved them both more than his own life , gave everything up for his village and the reason behind everything . Why he massacred the clan and spared only them .
Why Kabuto decided to fill her in was beyond her , but she didn't complain and decided to forget about that , a wrong move from the girls side because little did she know , Kabuto had his own plans for her , excluding Orohimaru this time . 
Being as young as she was , Aijin headed straight to the Hokage , Senju Tsunade , and demanded answers . Simply because she wasn't supposed to know about that , Tsunade sent her to a neighbouring village to keep her mouth shut , and long story short , after some time , Aijin defected from it , breaking Hokage's orders . She was marked as a missing nin , and the title of clan heir fell onto Sasuke , until he too left to go with the snake sannin , Orochimaru . Thus , there was no loyal Uchiha left in Konoha .

This is all great, it really makes me think she can be a actual Naruto character.
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Final Analysis- This OC is ready for a story, The only thing I really had to say was the fact with Kakashi, you can take my opinion into consideration but it is your OC and regardless of what you do she is ready for whatever you want to use her for, whether it is a fanfic or a roleplay she is ready. I can tell you worked hard on her. Thank you for letting me review your OC it was a honor.
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