"Alright kid. First thing you need is an alias", Stain told Midoriya when they reached Stain's apartment, if you could call it that. The wooden floor was wet in some parts and mouldy in others. The wallpaper was peeling off the walls and the ceiling tiles looked ready to collapse at any second. In short, this place was a mess. "The name Izuku Midoriya is on the government system, meaning they know everything about you. Without an alias, they'll know who you are instantly." Izuku nodded. Everything Stain said was making perfect sense. "But", Stain continued, "you can't just pick a random name. Your alias has to mean something to you or to someone else. My alias, Stain, represents how because I am a villain, I am automatically a stain on the governments prestige and reputation." Stain paused, then asked, "So, what's your alias kid?"
"Deku", Izuku responded almost instantly. Stain was a bit stunned. "Deku"is short for "Dekunobo", and translates to "good for nothing" in Japanese. Stain wondered why he would choose an alias like that when Izuku said, "Deku was what I was called in school. I was picked on a lot but Deku always stuck. I'm making Deku mine, and turning the weakness it brings into my strength".
Stain smiled. Being able to turn any weakness into a strength was key in this line of work. Stain's quirk was that he could paralyse anyone who's blood he tasted. It wasn't a strong quirk, but he used it well.
"Well now that that's out of the way, let's begin your training", Stain said. He got into a defensive position and said,"Hit me". Deku was confused. How was this training? He went up to Stain and threw a punch... only to be grabbed and slammed on the floor by Stain. Deku was dizzy when he got up, but know at least he knew how training was gonna go. He ran towards Stain, hoping to catch him off guard with a burst of speed, but no such luck. As Deku went to punch Stain, Stain dodged the punch then grabbed his arm and forced Deku onto the ground with his other arm.
"I said training was going to be difficult, didn't I?" Stain asked before getting up from the floor. Deku was not ready for this and Stain knew it. So he walked up to Midoriya, grabbed his arm and yanked it hard, dislocating it.
Deku collapsed, tears falling from his eyes and clutching his limp arm. "What was that for?!", he yelled at Stain. "This is your first lesson", Stain answered calmly. "Your challenge is to relocate your shoulder". Deku just stared at him. Surely he wasn't serious?
Deku then went slack-jawed as Stain grabbed his arm and dislocated it himself without the slightest noise of pain. He then relocated it, the only sound made was the "click" of the bone sliding into place. "Do as I did and you'll be fine", Stain said, waiting for Deku to complete the challenge. Deku grabbed his arm. It hurt like hell, but he had to do this. Remembering what Stain had done, he yanked his arm back into position as quickly as possible, crying out in pain. A satisfying "click" was heard, and then the pain was gone. He looked up at Stain, who smiled down at him. "Well done kid", Stain said, turning round. "You have one minute to recalibrate your arm before the next challenge", Stain said, the slightest hint of glee in his voice. Deku lied back on the wooden floor. This was not going to be easy.