The History of The Long Drawn War

(Backstory of the book MC read)

Once upon a time, 20,000 years ago. the continent of Angbotain was a place where all races co-existed together and lived in harmony. However, peaceful times did not last long, as the Demon King descended upon the continent. 

The Demon King sought to create a world where only the pure demons lived, he started by creating a massive army using his skills and powerful speeches. Once his army was ready, it did not take him long to start war against their archenemies - the humans.

The humans retaliated, and from a continent of peace it was engulfed with the flames of war. The demons were considered as spiteful creatures with nothing but hatred and were treated with contempt. After a long drawn battle The Demon King lost and sealed by the Five Cardinal Heroes. Now he has returned with more power than ever and will try to overthrow the human kingdom again. He can only be stopped with the help of the Five Cardinal Heroes.

"Oh, that's rather dystopic."

" Now that I know the cause, lets focus on improving magic and martial arts."

As he entered the Martial arts section, he used skill Appraisal to identify a good book on the basis of its ranks. (Note that all the books are now ranked according the raid levels rather than those of the monsters in the open)

He came across a gleaming blue book, exuding elegance, as he appraised, it turned out to be an extremely rare book. Upon closer inspection, it was found to be locked. 

Ding!!

The book-Silverlight Shadow Arts (Rank-Ss) has been unlocked due to the systems blessings.

As it was unlocked, he bought it for 15 gold coins and took it back to his inn.

"Use skill-Devour on the book."

Ding!!

The book- Silverlight Shadow Arts has been devoured, the author of the book is calling out to the host. Would host like to accept the invitation?

"Yes"

As Boruto was drawn into the book, he was greeted by an old shaolin master. 

"Heya kid, I go by the name of Sun Tzu"

"The renowned Sun Tzu!? Also known as the one who could reach the heavens?"

"That's about right" He said, with a huge grin.

"So, how were you able to unlock this book, I had blocked it with a barrier."

"Hi-Mi-Tsu da."

"Ooh you cheeky bastard.*Cough-Cough, Anyway it is something you wouldn't want to reveal, and you have the ability to break my barrier, so how about it, do you wish to learn my martial arts?"

"Of course."

"Well, let's start from the first stage. What according to you is martial arts?"

"It can be classified as the ability to be one with our weapon along with leveraging the power of each part of our body as a weapon."

"Looks like you have a fair understanding of martial arts. For starters, I'll show my techniques along with past experiences."

"With pleasure master."

Boruto along with Sun Tzu teleported to the past where Boruto was introduced to the first nine stages of the Silverlight 'Shadow Arts when he saw his master practicing these intricate techniques.

"Did you understand anything from it?"

"Well, I understood that this martial arts is about controlling the flow of mana and using it as an armor, it also increases our agility allowing us to boost our speed tenfold. We can also use this on our weapons using our ki we can be one with our weapon."

"I'm surprised you figured that out in such a short span, but that's just the basics, try looking it deeper."

Upon deeper inspection,

"It can also increase our speed, allowing us to use it to redirect the opponents energy and countering with a higher magnitude, about 4-5 times."

"Nice, that's good. This martial arts was created to face opponents who have a higher stamina and attack power than us."

Boruto was then shown records were he used the skills and the points to aim for. After returning from the past, he had learned all the nine stages of the martial arts.

"Now that you're done here, leave, and be sure to make great use of my martial arts."

"Yes master, thank you."

And Boruto was pulled out of the book which seemed to be empty now.

Ding!!

Skill {Devour} has been upgraded to level 2.

Species - Human (Boruto Uzumaki)

Level - 100 [ 70,000/100,000]

Strength - 125

Agility - 120

Magic - 130

Defense - 115

Intelligence - 70

Skills - {Appraise lv Max}, {Divine eyes lv 7}, {Arcane Magic lv 5}, {Mana Aura lv 8}, {Dagger Throw lv 4}, {Devour lv 2}.