BS: Changes

Everybody knew they'll change. Everybody knew something is not right. Everybody knew there'll be a repulsion. And everybody knew they'll stand against each other
What gives?

Aika is very loyal. How can SHE be a liar? She never lied to anyone, even to her brother. She fairly deals with others. She respects everyone the same way they respect her. She never gave rude comments and insults.

But everything has changed. When she and her brother were brought to this school to terminate students. Taught the use of syringes and weapons to terminate violent and mind-distorted students. And self-taught to do violent acts as well.

But then, as time passes, something IS not right at all.

Ryuu will suddenly vanish and Takashi-sensei will always see him walking in complete darkness with blood blotched all over his face and clothes. A blood-stained blade dropped on the ground and his eyes, instead of green, were red... and the iris are black, like cat's eye. Takashi would see his mouth always drenched in blood, determined that Ryuu is on a bloodlust.

He does NOT have fangs. He does NOT bite a victim's neck for sake of blood. He kills his victims with reason. Blood will be spurted everywhere and he will savour the taste of blood. That is WHY he'll be seen walking and his blood-stained hand on his lips.

When Ryuu saw Aika, he knew she'll freak out. The cherubim inside her is dying. She'll become a coward. But Takashi-sensei she'll FIGHT it. She'll fight the cherubim and REPLACE it with a demon.

Since a demon rests inside Ryuu, fate predicts the demon soul will be broken into two...for them to share.

But what can they do to MAKE it into two?

Without the witness of students, Aika killed three students. With reason. She narrated about her assault because the guys were harassing her and wanted to rape her outside the campus. She used the dagger she brought and slit through their stomachs. She even killed the last guy by jabbing the blade through his head.

Aika cried after her brutal murder of three guys. Ryuu saw her covered in blood but was not surprised or shocked. Because he was, too.

...

"How many?"
"Three...how about you?"
Snort. "Almost the entire gang."

...

What can THEY do to split the demon souls apart to become two?