The Sharingan is a Doujutsu that naturally occurs in a select few members of the Uchiha clan. The Sharingan does not automatically appear from birth in a user; instead, it will usually appear when the user is in a life-threatening situation, where the power of the Sharingan could save them. After this first appearance, the user can then call up the Sharingan any time they wish. The power of the Sharingan is judged through the number of tomoe in the eye, with a maximum of three in each.
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Tomoe 1: (200 posts) And a near death experience. The first level of sharingan grants the user exceptional analytical powers, allowing them to instinctively pick up on various visual clues with little difficulty.
Tomoe 2: (400 posts) And is achieved in a fight with a more powerful opponent. At the second tome it will grant perception great enough to see through genjutsu and to observe the movement and flow of chakra. Also at this form one can copy taijutsu but will result in great strain to the users body if the user has not received the training needed to use the move correctly.
Tomoe 3: (800 posts) And is achieved though a fight with a more powerful opponent. The third and final tome grants the most well known ability to memorize any technique that it witnesses with perfect accuracy. Also at this form one can perfectly mimic every move their opponent makes, even before they do, making it appear as if the user can see the future.
Half-Blood Uchiha
Pre-Mangekyou Sharingan: (1200 posts a full understanding of the sharingan and a fight with a more powerful opponent) At this level The user gets to use the Mangekyou technique's, but they are weaker and take more chakra to use them. Unlike the normal version the Pre-Mangekyou results in blindness so slow, it’s rare for a half-blood to actually become blind.
Permanent Pre-Mangekyou Sharingan: (2000 posts) And is achieved by taking the eyes of a fellow Half-Blood Uchiha. At this form blindness is not an issue because it does not exist. The power of this version is about 75% of the normal Mangekyou Sharingan and takes a bit less chakra to use. The tome the person you steal the eyes form result in the final power level. For example: If you have the Pre-Mangekyou Sharingan and you steal the eyes of a Tome 1 there will be a slight power increase but not much. But if a Pre-Mangekyou user steals another Pre-Mangekyou user or possibly a Permanent Pre-Mangekyou user the power will be off the scale.
Pure-Blood Uchiha
Mangekyou Sharingan: (2000 posts) It’s achieved by killing your best friends. Those who possess a Mangekyou Sharingan suffer from ever-deteriorating eyesight, a process that becomes faster through repeated usage and culminates in blindness. It has several different sets of abilities each very deadly.
Permanent Mangekyou Sharingan: (2500 posts) It’s achieved by taking the eyes of a fellow pure-blood Uchiha. The tome the person you steal the eyes form result in the final power level. For example: If you have the Mangekyou Sharingan and you steal the eyes of a Tome 1 there will be a slight power increase but not much. But if a Mangekyou user steals another Mangekyou user or possibly a Permanent Mangekyou user the power will be off the scale. Each sharingan ability is tripled their normal power level and like the normal version the Pre-Mangekyou blindness so slow, it’s rare for to actually become blind but possible