Fujibayashi Nagato

Can only be summoned as Assassin

Stats:
Strength: B

Endurance: D

Agility: B

Mana: E

Luck: B

Personal Skills:
1: Presence Concealment

1st: Bansenshukai
The Book was compiled by Nagato's descendant of all things about Ninja.

Nagato can use this to create Ninjas as a basis ability. But as an offensive Noble Phantasm, Nagato can use 6 abilities.

Thought - One gains the mentality of a Ninja.

Leadership - One gains the ability to command an army. As an offensive ability, the Master can use this to grant Nagoto increased power and the tactics of a ninja.

Open Disguise - It grants the ability to become anyone.

Hidden Disguise - It grants the ability to become invisible

Astrology - Grants the ability to predict a little of the future

Weapons - It grants the ability to summon any type of Ninja's weapon.

Together as a whole, Nagato can use this to become the ultimate Ninja where he becomes the pinnacle of a Ninja where all his stats become A along with new abilities.

Extra:
According to legend, Fujibayashi Nagato was one of the three greatest joninof the Iga, along with Momochi Sandayu and Hattori Hanzo. He was also the co-head of the Iga ninjas, along with Momochi Sandayu. Other than that, not much is known about him. In 1581, Oda Nobunaga launched a vicious invasion of the Iga province known as the Tensho Iga War, which decimated the Iga and Koga ninja clans. Survivors went into the service of Tokugawa Ieyasu, and Nagato was killed in the invasion.

Despite how little we know about his life, however, Nagato did in fact leave behind an important legacy: His descendants would eventually compile the ninjutsu knowledge he left behind to create the Bansenshukai. The Bansenshukai is a multi-volume compilation of the “secrets” and techniques of the ninja as written by the Fujibayashi clan—a lot of the information we have about ninjas today come from this compilation.

Fujibayashi Nagato was a leader of the Iga ninjas during the 16th century, with his followers often serving the daimyo of Oomi domain in his battles against Oda Nobunaga.

This support for his opponents would later prompt Nobunaga to invade Iga and Koga and try to stamp out the ninja clans for good, but many of them went into hiding to preserve the culture.

Fujibayashi's family took steps to ensure that ninja lore and techniques would not die out, and his descendant, Fujibayashi ​Yastake, compiled the Bansenshukai — the Ninja Encyclopedia.