The image isn't mine. This is Mari's outfit. Yes, I know that it's one of the outfits that Shay wears as a Templar. I just like the design of it.
This is the second book in the Trilogy. It's set around the time that the Akatsuki are formally introduced, but later.
I'm going to say this once: Itachi is Not an Akatsuki member. He's simply a rouge ninja.
Again: The characters from the actual games and books are Not Main Characters in this, they are referenced as Past members. Yes, I know that the Timeline doesn't quite match up with the full timeline of Mentors in AC. This is on purpose.
I used the Naruto Fandom Wiki as a source.
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Sasuke, Sakura, and Naruto managed to save Konoha, but there is more evil lurking around the corner for these three.
Shimura Danzō is dead, but that doesn't mean that the Templars will stop their plans. In Amegakure, a man by the name of Pain is looking over the files on Team 7. After setting the files down he calls a meeting for all high ranking members of the Templar Order. Pain declares himself the new Grandmaster and begins his master plan.
The Third Hokage is dead, has been for the past year, but Konoha needs a Kage more than ever. The council approaches Jiraiya about becoming the Fifth Hokage but he declines. They agree that Senju Tsunade would make a better Hokage and task Jiraiya with finding her. Naruto goes with him, hoping to learn more under the Toad Sage.
Sasuke has come to terms that his family was in the wrong but is still blindsided by his hatred for his brother, Uchiha Itachi. Lately he's been having thoughts of leaving the village in search of him.
Sakura is still far from being a Master Assassin. Training is all that has consumed her life, aside from a few missions, since the Konoha Crush last year. She yearns for something more. While Naruto leaves with Jiraiya, she and Sasuke find troubling signs that the Templars are back and ready for more.
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Characters:
-Haruno Sakura(MC 1)
-Uchiha Sasuke(MC 2)
-Uzumaki Naruto(MC 3)
-Hatake Kakashi
-Nara Shikamaru
-Akimichi Chōji
-Yamanaka Ino
-Sarutobi Asuma
-Inuzuka Kiba
-Hyūga Hinata
-Aburame Shino
-Yūhi Kurenai
-Akamaru
-Uchiha Itachi
-Gaara/Fifth Kazekage
-Temari
-Kankurō
-Tenten
-Lee Rock
-Gai Might
-Hyūga Neji
-Jiraiya/Toad Sannin
-Mitarashi Anko
-Morino Ibiki
-Haruno Mari(Oc)/Twenty-first Mentor
-Cousin
-Female
-Pain│Nagato/Twenty-first Grandmaster
-Hoshigaki Kisame
-Akasuna no Sasori
-Deidara
-Hiden
-Kakuzu
-Zetsu(Black and White)
-Tobi│Uchiha Obito
-Konan
-Senju Tsunade│Slug Sannin/Fifth Hokage
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Assassins:
-Haruno Sakura
-Haruno Mari(Oc)/Twenty-first Mentor
-Yamanaka Ino
-Uzumaki Naruto
-[Put any of the other characters that you want here, including any OC you want to; Except for Sasuke, he'll be there in the third book]
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Templars:
-Pain│Nagato/Twenty-first Grandmaster
-Hoshigaki Kisame
-Akasuna no Sasori
-Deidara
-Hiden
-Kakuzu
-Zetsu(Black and White)
-Tobi│Uchiha Obito
-Konan
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Basic Timeline V2:
1. Bayek and Aya start up the Hidden Ones in Wind Country; Rayhan leads the Hidden Ones before the Transition to being the Brotherhood; Al Mualim, the First Mentor is killed and succeed by Altaïr Ibn-La'Ahad, the Second Mentor
2. Haruno Minori(Oc) becomes the Third Mentor and works under Otsutsuki Hagoromo and Otsutsuki Hamura 1035BKE(Before Konoha Era)
3. Kaguya is sealed and Haruno Atsushi(Oc) becomes the Fourth Mentor 1000BKE
4. Haruno Shiori(Oc) becomes the Fifth Mentor 974BKE
5. Haruno Nori(Oc) becomes the Sixth Mentor after a brief period of inactivity from the Assassin's Brotherhood 944BKE
6.The Assassin Brotherhood is dismantled for 30 years and then rebuilt by Ezio Auditore, the Seventh Mentor 900BKE
7. The Brotherhood is in control and the world is at peace until The Warring States Period 900-47BKE(897 years)
8. Haruno Amaya(Oc), the Eighteenth Mentor is killed during the Waring States Period 13BKE
10. Haruno Kazuo(Oc), the Twentieth Mentor is killed alongside the rest of the Haruno Clan that resides in Sunagakure 123KE(Konoha Era)
11. Haruno Mari leaves Sunagakure and lives in Konoha with Haruno Kizashi and Mebuki, her Aunt and Uncle 124KE
12. Haruno Kizashi and Mebuki are killed 143KE
13. Haruno Mari(Oc), the Twenty-first Mentor, takes care of Sakura and trains her 143KE
14. Book 1 begins with the creation of Team 7
15. Book 1 ends 1 year after the Chunin Exams
16. Book 2 starts with the introduction of the Akatsuki(just later than cannon and Itachi isn't a member)
17. Book 2 ends before the Fourth Great Shinobi War
18. Book 3