My Hero Academy x Assassination Classroom REDOING

Weakness

Nagisa POV
While we finished training with Mr.Karasuma the same green magical circle appeared below all of us and we were transported back to Class 1A's dimension. The most shocking thing is that the green haired boy lost all his memories including himself. After a brief summary between teachers we went to our rooms to rest and to our surprise our stuff were untouched, nor moved.
The green haired boy was behind me and Karma who were going to our room. He seemed more serious and on-guard than the last time we saw each other. He walked in the room and sat on his bed while looking at us. It felt like he was seeing right through us and it made me a little uncomfortable. "You must be Karma and you Nagisa, right?" He asked pointing at us. I nodded and he was now staring at me and I couldn't read his intentions.
Karma stood in front of me, "Why are you staring at him like that?" Karma asked, he seemed angry at Midoriya. "I'm just looking to remember your faces. Don't worry I'm not interested in taking someone else's boyfriend." He said with a smirk. Me and Karma both blushed, "I-its not like that!" I yelled. He raised a brow and said, "Well I don't think he thinks that way." He smiled while looking at Karma who was the same color of his hair and brighter.
After settling down Mr.Aizawa came in the room asking for Midoriya who was laying on his bed ignoring him at first. He groaned and left the room with the teacher.
Me and Karma were the only ones left in the room, "Don't you think he changed a lot. He gives this dangerous vibe as if telling us to be careful with him." I said and Karma stayed silent. He seemed upset for some reason but I didn't want to bother him so I didn't ask.
A few of my classmates stayed in their room to rest while some were in the living room. It was already the end of class so Class 1A must be coming back to the dorm. After a few minutes they came and they were dretched in their sweat and panting as if they just ran the marathon. Midoriya was sweating but he didnt seem tired or exhausted like his other classmates.
They went to their rooms and Karma followed them, what was he after? I quietly followed Karma from a distance to see what he would do. After they went in the room I stayed behind the door to listen to their conversation. 'Why am I so worried about their conversation? Why did I follow them like a stalker?' I was about to leave when I heard them talk.
"What do you want?" Midoriya said, his tone was cold and scary.
"Why did you bring us here?"
"Look man we already talked about this, I don't know how am I able to bring you who are from another dimension to another okay? I can't control it." Midoriya explained.
"Why can't you control it? It's your power, what kind of person can't control what is their's? Don't you people learn to control it as soon as your powers appear?" Karma said while raising his voice.
"Karma I don't want to fight with you. I-"
"What does 137 mean?" Karma asked and everything went silent. 137? What is Karma talking about?

Karma POV
I was in the living room with a few of our classmates waiting for that broccoli head. Once Class 1A came they were exhausted but Midoriya wasn't, that is interesting. I followed them quietly and hoped that Nagisa wouldn't notice that I wanted to cause trouble.
I need to know his weakness but first I have to make him mad. If I am able to find his weakness and make him enrage he could be expelled of the school and we could be sent back home. Once we are in our dimension we can go as usual and kill Korosensei without worrying that others will.
After we entered our room he stopped and asked, "What do you want?"
"Why did you bring us here?"
"Look man we already talked about this, I don't know how I am able to bring you who are from another dimension to another okay? I can't control it." He said. Instead of making his angry this is making me angry, it this guy just toying with our lives.
"Why can't you control it? It's your power, what kind of person can't control what is their's? Don't you people learn to control it as soon as your powers appear?"

"Karma I don't want to fight with you. I-" I interrupted him because what I wanted was for him to be angry and try to fight.
"What does 137 mean?" He flinched for a moment and glared at me, I think I hit a soft spot. His aura changed to a dangerous one that I felt a little a shiver go down my spine. The day that we were sent back to our dimension I saw a number tattooed in the back of his neck while he was hugging our teacher.
I didn't think much of it but to think that it was something that could trigger him is unexpected. I smiled, 'this is his weakness.' He kept a straight face but his aura was becoming more deadly.
"You better be careful with what you say in front of me, I never now what I may do if you piss me off. Yesterday I sended someone to the hospital because he thought I was his play thing." He said with an insane smile and I knew that I shouldn't ask any further but this is one step closer to making him back away from Korosensei.
I felt a gust of wind and Korosensei appeared before us, "That's enough kids, it time for bed. Tomorrow is another bright and lovely day so you two can try and kill me." He said and Midoriya left the room to find Nagisa watching us. He must have knew I would cause trouble when I followed Midoriya.