Holy Spirit Beast

"AZURE!!"

Gyutarou and Ye Xinghan were dumbfounded.

Gyuutarou never expected his little sister to be so talented in Glory City, even her talent a level higher than the only legend ranked demon spiritualist, Ye Mo.

But, Ye Xinghan surprised for different reason. When the crystal on Ume's palm started shining, he felt an indescribable ancient aura spread out. (I don't even know how ancient aura feel lol, maybe the smell of dust and decaying dust. Anyway, this is only ff.)

Finally, Ume opened her eyes and became slack jawed when she noticed the crystal. 

"Onii-chan! Its azure, its azure!!" Then, she started to jump around like a little kid. She even throw the crystal away when she started running towards Gyuutarou and hugged him.

If only Ye Xinghan didn't catch it, then the crystal would be shattered on the floor. (Idk if its fragile or not. But I need words count hahaha)

These crystals were bought by Ye Xinghan's own money. Right now, he didn't have a lot of allowance. So, the crystals value were quite a lot for him. (Be frugal guys)

Ye Xinghan started to look at the illusory figure in the center of the crystal.

It is a.... turtle?

An ordinary black tortoise to be exact, but with a small horn on its head.

But there's no way an ordinary looking turtle could emitted such aura.

So, Ye Xinghan started to skimming through the book again.

And then he finally stop at a certain book.

If he remembered correctly, this book was only recently unearthed at the same time when Ye Zong brought back Ye Han.

Ye Xinghan didn't fully learned the language of this book because the book was estimated to exist far before the age of darkness. 

Sure enough, when he reached the page in the middle. He found a soul form that was exactly like the one Ume has.

"Mystic.... Deep.... Turtle?" Ye Xinghan muttered.

If he remembered correctly, than this soul form was the martial spirit of Xu Sanshi Soul Land 2!

"Mystic Deep Turtle, wow the name is so cool! What does it do?" When Ume heard Ye Xinghan, she stopped jumping and approaching him with glimmering eyes.

"Mystic Deep Turtle is a spirit beast (intentional) excelling on defense and endurance. The shell is so hard even a divine weapon would have a tough time breaking through.

Their vitality is top notch as well. At its peak, even regrowing limb would be an easy matter." Ye Xinghan explained. But there was a thing that he didn't say

'Turtle as the body, snake as the tail. This is the true form of Xuanwu, the original Divine Beast in Chinese culture. No wonder I felt an ancient aura coming from the soul crystal.

In the Demon Slayer anime, Gyutarou always hiding inside Ume. His nature is also cunning and smart. Just like a snake.

They cannot live without each other, as they are one body and one entity.

Maybe, there are a lot of secret waiting to be uncovered regarding them.' 

"Why are u went silent?" Suddenly, Gyuutarou asked as he noticed the frown on Ye Xinghan's forehead.

"Nothing, your sister cultivating journey would be a lot easier than you since this mountain range has a lot of demon beast with water attribute.

Are you envious perhaps?" Ye Xinghan smirked as he looked at Gyutarou.

"I always believed that my sister is destined to have a good life. Naturally, there is no need to feel jealous." Gyuutarou said with 'a matter of fact attitude'. He looked happy but tried to hide it. Ye Xinghan of course didn't miss the slight gesture of Gyuutarou who was twitching his mouth to stop himself from smiling.

'What a tsundere' Ye Xinghan thought while shook his head.

Then he continued, "I have a little sister around 4 years old.

What about if Ume become my sister's personal baby sitter?"

Gyuutarou regained his calm when he heard those words.

Then he spoke with chilling voice, "What are you trying to pull off?"

But, Ye Xinghan only laughed it off and shook his head, he said "You always become sensitive about anything related to your sister huh." 

Gyuutarou replied instantly, "The deal was only between you and me. I don't want to bring Ume into danger."

"Of course not." Ye Xinghan said, "The main reason of me bringing up this matter was actually quite simple."

"I want you to have a peace of mind, that is beneficial for your future."

Gyuutarou only raised one of his eyebrow at the sentence.

Ye Xinghan continued, "I need a legitimate reason to protect your sister"

No

"The Snow Wind Family will protect your sister!"

"There is no greater reassurance than this, right?"