An enigmatic man walks with two of his children through a forest. He said,

"Do you both understand your purpose and position in the Death Stratum?"

"Yes, father."

"You don't know if you're still on your knees about your brother dying. This is survival of the fittest. Your brother wasn't strong enough to survive; it's that simple."

"I understand."

The child walks and thinks for a second,

"Father, who exactly is Yukashika?"

The father grins slightly.

"Good question. Yukashika was a legendary historical syneji artist who spanned 1800-1900, peaking during the Okina generation, in 1840-1850. All of the strongest syneji artists gathered their strength, and it took the strongest grand master sword artist in history, Takyon Yuzuru, with the rest of the generation to defeat him. They, however, couldn't kill him and resorted to methods of sealing him. It was known as the The Immortal Sendanoshi War."

The father says,

"When Yukashika was sealed, it was believed he had so much isotonic force that his dying could cause a massive earthquake, nothing like anyone has ever seen, because isotonic force is derived from faultlines. So they took his body and sacrificed themselves through a sacred pledge, the condition was that with their body they would take his soul and split it into 4 fragments. These fragments were known as Sendai Soul Seals. Stone-like objects that contain 1/4th of Yukashika's isotonic energy and isotonic force. Every seal harbors the sacrificed person's soul along with Yukashika's. The Society of Artistry contains 2 out of the 4 seals; the other's whereabouts are unknown to the public. The first seal is located somewhere in Yokohama under severe surveillance, and the second is located somewhere in Osaka. No one has even attempted to steal it. "

"Why not?"

"Well, if Yukashika truly was to somehow come back, I'd be better if he didn't have the seals, and everyone can universally agree on that."

"People still fear Yukashika to this day?"

"He was beyond a monster. Even Tsuyo Hayoku would greatly struggle against him."