In tribute to one of my favorite character of all time, Itachi Uchiha, I decided to create him in Pathfinder. Please note that this build is my interpretation of how I perceive him. This build is RAW legit. So without further introduction, here's the build.
Itachi Uchiha - LN
Level 18 (10 sorcerer 'Sage archetype'/ 7 Demoniac / 1 Monk)
Bloodline: Arcane
Stats* High fantasy
STR: 14
DEX: 22
CON: 20
INT: 26
WIS: 20
CHA: 14
* This is an endgame build, so I have a Belt of Physical Perfection +6 and a Headband of Mental Superiority +6
AC: 35 (10+6'dex'+5'wis'+4'mage armor'+5'ring'+5'amulet')
Initiative: 8 (6'dex'+2'reactionary')
Saving Throws:
FORT: 19 (9'base'+5'con'+5'cloak')
REF: 18 (7'base'+6'dex'+5'cloack')
WILL: 23 (11'base'+5'wis'+5'cloak'+2'Iron will')
FEATS*: Still spell, silent spell, iron will, demonic obedience, intensified spell, maximize spell, spell perfection (disintegrate), spell perfection (freezing sphere), spell focus (evo), spell focus greater (evo), deflect arrow.
*You can add craft wonderous item if you feel like the price of your items will be to expensive. Also, still spell and silent spell are just great to have in general if you're a sorcerer but are not required for this build. You can replace those feats by Improved initiative or the Spell penetration chain.
Special abilities:
Sharingan
The Sharingan grants it's wielder two broad abilities. The "Eye of insight" and the "Eye of Hypnotism". Basically, it gives it's wielder more power and power in Pathfinder is represented by a bonus to a stats. This is why the demoniac prestige class is for me the best choice to mimic the Sharingan. First of all, you get a demonic mark that can be represented by the Sharingan in your eyes. Second, when you activate your Energumen ability "Sharingan" you gain a profane bonus of +6 to a stats...what more can I say. The only thing is that you'll have to negotiate with your gamemaster since you need to be Chaotic Evil to have access to this prestige class. I, for my part, told my GM that I had killed my clan for the sake of my country and that's how I got my Sharingan. I also told him that I wanted to create Itachi so he understood my motives. In the end, he allowed me to get this prestige class even if I was LN but he removed my ability to summon demons that I gain with the class which I thought was fair.
Amaterasu
Amaterasu produces black flames at the focal point of the user's vision. In most situations, this makes Amaterasu impossible to avoid. However, if the target can move fast enough to prevent being focused on, Amaterasu will miss them when it's cast. For me, the equivalence of Amaterasu in Pathfinder is Disintegrate. In order to hit with disintegrate, you need to make a ranged touch attack roll which is perfect because Amaterasu can miss if the target is fast enough to dodge the hit. Disintegrate deals a lot of damage. If the target fails his fortitude save, the spell deals 2d6 per caster level. That's 36D6... Since we took spell perfection (disintegrate), we can maximize for free all our disintegrate and combine with a rod of persistent spell... it's deadly. 36d6 maximized is 216 dmg... Since disintegrate also destroy walls of force and other stuff, it fits the idea that Amaterasu's flames burn forever. The way I roleplay disintegrate is instead of firing a "ray out of my finger", I fire a "ray out of my eyes". OFC the whole eye thing doesn't work if I'm grapple but you get the point.
Demonic Illusion: Mirage Crow
This genjutsu traps a victim in a powerful illusion. When used, the genjutsu projects a torrent of crows, leaving the opponent at the user's mercy. The spell scripted hallucination is the equivalent of this technique. What's great about this spell is that if the target fails his will save, he starts to hallucinate. Note that unlike Major image, the target is the only one who sees the hallucination. I use it to make the target see a horde of crows flying around him. Note that for all illusion spells, I suggest you speak with your GM to see what you can and cannot do since illusion spells usually have no limits. In my case, my GM decided that if my target was affected by the spell, he would have a lot of penalties (on AR, AC, Saves, etc.) a little bit like the witch abilities to cackle and misfortune but way better. Honestly at this level there are so many "save or die" spells that this is a legit ruling.
Fire release: great fireball technique
The spell fireball is the equivalent of this technique. You can use the trait Magical lineage on that spell and add the metamagic Intensified spell for free to make it better over time.
Fire release: Dragon breath's
The spell dragon breath's is the equivalent of this technique. You can use the trait Magical lineage on that spell instead to add the metamagic Intensified spell for free to make it better over time.
Water release: Water bullet technique
The spell cold ice strike is the equivalent of this technique. you basically fire a blast flurry of ice sliver from your hands that affect every target in a 30-ft. line and deals 1d6 pts of cold damage per caster level... and it's a swift action!
Water release: Dragon bullet technique
The spell cone of cold and the spell freezing sphere are the equivalents of this technique. I decided to take the feat spell perfection (freezing sphere) because adding the metamagic maximize to this spell for free is FUN TIME. 40 ft radius burst of love!
Shadow clone technique
Lower level, the spell mirror image is the perfect equivalent of this technique. When you get higher level, you can use projected image which allows you to create a clone of yourself that you can project your senses into to talk, move and even cast spells while your real body is hiding somewhere. Mislead is also a great spell to consider.
Tsukuyomi
Tsukuyomi requires eye contact to be performed, trapping the target within an illusion completely under the user's control. Itachi's prowess with the technique has allowed him to alter the perception of time with ease within the genjutsu to make a few seconds seem like many days as a means to torture the target. This results in the victim suffering psychological trauma that incapacitates them for a considerable period of time. The equivalent of this spell, in my opinion, is phantasmal killer. On paper, it might not be the best spell since the target has to make two saves but since it's a powerful illusion that kills the target psychologically (from fear) I decided to go with it.
Izanami
Whilst under the effects of the technique, the target stands motionlessly as the loop of events continually replays inside their mind. However, because this technique was created to reprimand and save the users of Izanagi, the victim is able to escape the infinite loop if they can acknowledge the real results of their actions and in doing so, accept their fate. The spell MAZE is the equivalent of this technique. I love the fact that the target is stuck in a maze and must make an intel check to escape it. They have to accept their fate if they want to escape the maze. ;)
Susanoo
Finally...the ability we were all waiting for. Since we went down the path of the sorcerer, there's not a lot of option that mimics this technique. The best option I found was Firey body. This spell transforms your body into living flame. You are immune to blindness, critical hits, ability score damage, deafness, disease, drowning, electricity, poison, stunning, and all spells that affect your physiology or respiration. You take only half damage from acid or electricity. It's not the best equivalent of Susanoo but I don't think Pathfinder was meant to have something that overpowered lol.
Conclusion
Since in Pathfinder you cant be "good" in everything, I chose the Jutsu path. With this build, your BAB is somewhere between 12 and 16 unbuffed which sucks at higher levels. The main focus of this build is to Blast with evo spells, C.C with powerful illusions and buff your team with spells like Haste, Heroism, and so on.
With this build, you need the trait magical knack to gain that extra 2 caster level that you lose with the first level of Demoniac and Monk.
Battle simulation
Round 1
Free action: activate Sharingan (Energumen) to gain +6 profane bonus to intelligence
Move action: position myself on the battlefield
Swift action: Water release: water bullet technique!! (cold ice strike)
Standard action: Water release: water dragon bullet technique (Maximized freezing sphere)
Before round 2: You make a couple of saves and fortunately, your saves are good so you succeed. Then the boss is piss so he decides to charge you and hit (35 AC is only good to dodge the lowest BAB hit at this level)
Round 2
5 foot step so you don't declare AoO
Standard if boss main save is not fort: Fool... feel the eternal flames of hell! AMATERASU! (Maximized Persistent Disintegrate) The DC is 27.
Standard if boss main save is fort: Accept your fate...you are weak! Izanami. (Maze)
Swift: Maybe another Water release: water bullet technique!! (cold ice strike) for fun time
_________________________
Thank you for taking the time to read all this! I hope you liked the build and I would love to see your comments on whether you would change something or how you would create Itachi in Pathfinder.
Have you looked into occult classes? Mindscapes might model some of the genjutsu better, and the Mesmerist is an entire class based around interesting effects coming out of one's eyes (and an optional ability alows you to dodge by turning into a raven).
Some other good spells for an adept Uichiha:
Burning Gaze
IzangiSubjective Reality