"Now during the Shakespearean era-"
A knock was heard at the door.
Karasuma opened the door and walked in.
"Good morning students."
One of the girls smiled brightly.
"Good morning Karasuma-sensei!"
Karasuma looked around and then at the tentacled monster-teacher.
"Another late arrival will be here soon, he currently doesn't know about your teacher yet. He was on sick leave until just recently. He is ranked second in the school, but decided to join you here."
Some of the guys' jaws dropped.
"Eh?!"
"He should be here any second."
Almost on cue, there was a knock on the door.
"May I come in?"
A monotone male voice came from the door.
Karasuma and the students took a deep breath.
"Yes you may."
The door opened and a tall black haired boy walked through.
He wore a long black cloak that had red and white clouds randomly placed along the cloak.
He had onyx black eyes which appeared to have no irises, just black iris sized pupils.
The boy wore sandals.
He walked to the front of the class and bowed.
"It's a pleasure to meet you, I am Sasuke, Sasuke Uchiha."
Nagisa looked around.
'Where's Koro Sensei?'
He thought.
At this point, Karasuma told everything to Sasuke, explaining the situation.
Sasuke chuckled, earning some surprised looks.
"Huh, I was wondering what happened to the moon. So we just have to kill him by the end of the school year?"
"Er- Yes, that's...'all'"
"So where is this 'monster' teacher?"
Koro sensei flew in, with his usual grin on his face.
"hn, so you're my teacher, eh?"
The teen held out his hand.
"It's a pleasure."
He smiled, with his eyes closed.
Koro Sensei hesitated, but held out a tentacle, shaking Sasuke's hand.
Sasuke squeezed the tentacle hard, opening his eyes.
His eyes had changed from onyx black to onyx black with a blood red design.
"Chidori."
His hand glowed with an aura of electricity.
The tentacle melted off as a result.
"Oh my, did I do that?"
The boy grinned, "My apologies, sensei."
Everyone was surprised.
"W-What the hell was that?!"
One of the students shouted.
"I'm glad you asked."
Said an exact replica of the boy, standing in the back of the room.
"I am what you might call, a shinobi."
The Sasuke at the front melted, becoming mud.
"I am the ultimate assassin."
'The ultimate...assassin?'
Nagisa thought to himself.
Sasuke smirks.
"You see my eyes, they're quite special. I can see and do things no normal human can do. I can see speeds of up to but not limited to- Mach 21."
"EH?!"
Even Koro Sensei was surprised.
"I also have a photographic memory, so that also helps. I am also stronger than any normal man. I will give an example. Give me something to work with."
Terasaka made a "tch" sound and tried to throw a rock at the boy's head.
Sasuke grinned, catching it with ease.
"Now then. See this rock?"
He squeezed his hand and crushed it in between his fingers.
When he let go, dust fell from his hand.
"So.. Where shall I sit. Sensei?"
Koro sensei pointed to an empty seat.
"I can't wait to see what kind of assassination you will create with your classmates, Mr. Uchi-"
"Sasuke is fine, no need to be so formal."
"Because I'm a monster, bent on destroying your planet?"
"No, because you're my teacher."