Sanctuary (Karma Akabane x OC)

Sensei vs Student

"Christ, this place looks like a boxing ring," Professor Bitch dictated, scanning the classroom.

The students had moved their desks to the sides of the room, acting as a sort of circular barrier. Koro-sensei and Itona were stood facing each other within the ring, each opponent staring the other down.

"This should be interesting," Karasuma responded, hanging back in the corner, "I've never seen an assassin take this approach, he must be willing to defeat the target using only pure strength."

"Let's set out some rules," Shiro declared, standing behind is protege.

"We'll confine the fight to one room, step outside the boundaries and your life is automatically forfeited."

"As if the losing side will stick to that.." Sugino muttered quietly.

He was stood cautiously beside Karma and Katsuna, both students not taking their eyes off the opponents in the middle of the room.

"Trust me, Koro-sensei will uphold the rules out of a sense of pride," Karma uttered in response, "He's all about keeping up his reputation as a teacher."

"It's Itona you should watchful for, he may abide by the rules now due to being so confident," Katsuna motioned towards the new classmate, "But later, I'm not so sure."

"May I add one other rule," Koro-sensei asked, his eyes trained on Shiro, "Hurt one of the surrounding spectators and your life is forfeited."

"Seems reasonable," Shiro shrugged, raising his hand, "Begin on my signal."

"Assassination....... BEGIN!"

Milliseconds after the announcement, a high-speed attack sliced through the air, severing one of Koro-sensei's tentacle before one could even breathe.

The spectators gasped in shock at the sight before them, staring not at the cut off tentacle but instead Itona himself.

"Impossible.." Koro-sensei whispered in utter astonishment.

It was as if his spiky hair was alive with snakelike movements.

"He has.... tentacles."

Katsuna and Karma side glanced each other, both silently sharing the same revelation.

So that's how he stayed dry, he simply batted the raindrops off.

"How.. HOW?"

Koro-sensei growled menacingly, his pitch-black face bulging with blood vessels, displaying complete rage.

"TELL ME WHERE YOU GOT THOSE TENTACLES!"

The students had only been showed this expression once before when Teresaka's group placed Nagisa's life in danger, however this time, things seemed different.

This was Koro-sensei's true hidden wrath.

"Are aren't obligated to share that detail with you unfortunately," Shiro grinned, sickly pleased with Koro-sensei's aggravation towards the matter.

"I see... clearly we need to have a long chat," the teacher seethed, baring his teeth sinisterly at the man in white.

"Too bad you'll be dead before you get the chance, " Shiro dared, lowering his eyes in response.

He shone a blinding purple light hidden under his white sleeve, the light somehow effecting Koro-sensei severely as the octopus stumbled back in an attempt to shield himself.