Observe

After resting for one hour, Isshin came back to the stone-paved ground.

"Now, I will be teaching the Observation class so let's start with that! Follow me to the basement!" Isshin gestured for the kids to follow him and walked inside the big hall.

He walked near the back right corner of the hall, beside the raised platform, and pulled the floor up to reveal a set of stairs leading to a dark and damp basement.

He walked down the stairs, with the kids behind him, and pulled a random lamp from a crevice in the wall. He lit up the lamp, which dimly lit the surroundings. Instead of making the place more familiar, the lamp enhanced the eerieness of the basement.

Isshin walked off the stairs after reaching the bottom and walked a bit of distance, making sure the trainees followed him.

Ivar, who was closely following behind Isshin, wrinkled his nose as the nauseating smell of rotten flesh assaulted it.

"Ugh! What is the smell!" One of the trainees remarked, waving his hands hear his nose.

The other trainees were in similar situations, barely holding back their vomit. They had definitely become stronger from the previous day's experience.

After reaching a distance of about 50 steps from the ladder, Isshin stopped and said, "You will sit down here now. We are going to release a few hundred hungry-enhanced rats. They will try to eat you alive and the only way to stop them is to kill them or literally pull their tail, which will keep them paralyzed. Also if you pull their tail don't kill them. if you do, you know what will happen."

Isshin warned the trainees and blew the fire off the lamp. Black darkness enveloped the trainees as they scrambled together and sat down.

Creakkkk-

The sounds of metal rubbing were heard, as a flurry of hurried steps enveloped the silent darkness. 

The steps seemed to be getting louder and louder, planting a seed of panic in the hearts of the trainees.

"Shit." One of the trainees cursed. 

At this point, the trainees had all huddled together, sitting close to each other, knowingly or unknowingly, in the shape of a circle.

Sensing from his touch, Ivar guessed that he was somewhere in the middle of the circle. The trainees who had just cursed were from the circle's very outer layer.

Squeak-Squeak-

"Shit. Shit. Shit. They are swarming me- AGGGHHH!" A primal cry reverberated in the ears of the trainees as one of them screamed at the rats digging through their skin.

Ivar sensed the predicament they were in. If there were really hundreds of these rats then they can simply climb over the body of the people in the outer layer and overwhelm all of them.

"Everyone! Stand up and defend your legs. If you stand up you only have to defend your legs!" Ivar stood up as he shouted.

Hearing Ivar stand up, most of the trainees stood up. Most of them that is. One of them, the one who was attacked first, was still sitting cross-legged as he kept punching his legs cursing the rats.

"Shit, Fucker! Take this." The man screamed as he punched one of the rats which was extending the hole in his legs.

He banged his sword on the ground, producing a metallic sound, trying to hit and possibly kill one of the few dozen rats crawling towards him. 

He pushed himself with his hands and crawled in a random direction. It didn't matter where he crawled to anyway as he couldn't see anything in the lightless environment.

A ray of hope took seed in his mind as he finally touched what seemed to be the shape of a human leg.

"Brother! Sister! P-please save me! I will serve you all my life." The man stuttered as he tried to kick the rats away from him. He touched the feet of the person who seemed to be sleeping on the ground.

The person remained silent despite the man clinging to their leg.

"Please. Please, great sir! I will do anything." Snot and tears covered his face as he tightened his grip on the sleeping man's legs.

As he gripped the leg too hard, a grotesque pop reached his ears as the disgusting taste of rotten human flesh reached his tongue.

"NO. NO. PLEASE DON'T BE DEAD. No." The man, now filled with despair, buried his face in the leg as he accepted his face.

He stopped resisting the advances of the mice as they slowly crawled up his legs, tasting the delicious and fresh human flesh. The man looked back at his body for the last time, but his vision was enveloped by the slightly glowing red eyes of the mice, who seemed to be mocking him with a smirk.

Even at the smirking face of death, a man couldn't accept his fate. 

"NO– NO– SAVE ME! MOMMMMM–" The man resisted for the last time, trying to cut down the smirking faces with his sword. But the mice didn't stop till they reached his eyes.

The man realizing their intention swung his sword at his own eyes, killing one mouse, but there were more than one. The other mice took the opportunity to dig through his eye socket and gnaw on his brain.

"Pl..ease– Mom. Don't… wat…die.." His weak voice dissolved among the sounds of the mice munching on his flesh and brain as he remembered his family for the very last time.

***

Ivar swung his sword cutting off the mice clinging to his legs. 

"Hey Ivar, You alright?" A familiar voice whispered in his ear.

"Cohen? Is that you? How did you find me." Ivar questioned Cohen, who found him among this many people.

"I don't have time to explain much, but I used my ability to visualize your silhouettes and guessed you were Ivar. You are quite tall for our age so it was easy." Cohen hurriedly explained.

"Oh. So what do you want to say?" Ivar grunted as he swung his sword killing a mouse.

"I can use my ability to defend us by binding the mice to a place. While I do it, you kill them. That way I can keep resting after they empty out for a while and I won't be overwhelmed."

"Sounds good to me." Ivar gave a thumbs up as Cohen started binding a few mice approaching them.

"They have been bound. Three behind us, Two at left,..." Ivar and Cohen started slaying.

After an hour which seemed like an eternity to the trainees, the mice which were trying to eat them suddenly changed directions and ran back to where they came from.

Creak–

The sounds of metal gate closing were heard as the mice were once again trapped back in their cage.

A man with a dimly lit lamp appeared in front of the trainees as he clapped.

"Good work today, only one of you died and two are injured." That man was of course Isshin!

Ishhin looked at the faces of the trainees and looked at the bites on their legs. He scratched his chin for a while as he thought. "Doing Observation class as the first one might be a bad idea. Let's do it at the end of the day from now on!"

"Oh, follow me! You have impersonation class next!" Isshin ordered the trainees as he walked forward with the lamp in his hand.