Wisp

Newton's Third

  The robot smashed through Izuku's smoke wall yet again, scattering the black wisps of smoke everywhere. The greenette sighed, accepting the offered water bottle from Aizawa.

  "There's something I'm missing.. you shouldn't just be able to smash through solid objects like that. Once I figure out what I'm doing wrong, I should be able to stop any attack with little effort." He muttered.

  "We have to pack up for now. Today you'll be having your first (actual) heroics lesson. Get your costume on and head out to the bus bay. We're going to a special facility for rescue training."

  The greenette sighed and got to his feet.

  "Alright. I'll think on it when I get home." He said.

  Izuku's costume was quite simple. A dark green, almost black jumpsuit with small black exhaust ports at various places around his body. Cheekbones, shoulders, heels, elbows, shoulder blades and knees. They were so that he could release smoke all around himself at once for maximum effect. It was especially useful now that he could create punch resistant shields with a single thought. Theoretically he could also stop bullets, but he wasn't keen on finding out. Until he figured out what he was missing.

  He had a black utility belt with two emergency medical kits, a few rolls of capture tape, some cigarettes and other useful knick-knacks. He also had a mask, which was where the exhausts were all connected to. It was a plain rebreather that covered his mouth and nose, which could hang around his neck if he wanted.

  Izuku met Aizawa outside, where they boarded the bus and spent fifteen minutes driving to the special rescue training facility.

  The greenette followed Aizawa off of the bus, where they met the rescue hero Thirteen outside a large dome.

  "Good morning Mr Midoriya! I've been hearing some good things about you from my colleagues! Welcome to the USJ, a facility I have designed to simulate the most common disasters a hero will eventually face! Please come inside!" The hero exclaimed.

  The two heroes and one student entered the facility and stopped at the top of the large staircase leading to the central plaza below. Izuku looked around the large dome in barely contained awe.

  There was a lake, a mountain, a pair of separate domes altogether covered in painted on flames and blue waves, a crumbling city and a rocky outcrop.

  "Floods, fires, storms, landslides and earthquakes! These are just some of the scenarios you will come across in your career! I'm sure Eraserhead here has been teaching you how to wield your quirk offensively! Well, with me you will learn how to use your quirk to save people from disasters such as these! Follow me!" Thirteen exclaimed.

  They went down the stairs and headed to the crumbling cityscape. They moved to the centre of the zone, where there was an intersection with roads leading off in several directions.

  "Welcome to the Earthquake zone! Possibly the most common disaster you will come across, an earthquake in or around a populated area! Now, these buildings are made to be unstable, so we will need to be cautious, however most of them can only collapse if triggered by the facilities main computer!"

  Izuku followed Thirteen into the nearest building, Aizawa right behind him. The rescue hero led them upstairs to an open room with large cracks running along the floor, walls and ceiling. On the other side of the room was a training dummy slumped against the wall.

  "You see the cracks around the room? Unless you can fly, it's too dangerous to try to rescue the civilian in this situation. You need the floor to be supported from underneath, or the cracks to be fixed by someone with a specialist quirk. So long as you wait and don't disturb the building, the civilian will be safe until you can rescue them without worry. 'A body at rest will remain at rest until acted upon by an external force'."

  "Newton's First law of motion." Izuku said.

  Thirteen gave a thumbs up, the white eyes on her spacesuit narrowing as though she were smiling.

  "Exactly! Now, if we head downstairs I can show you how to..."

  Izuku wasn't listening.

  Newton's laws were spinning around in his head. Specifically, the third one.

  Every action has an equal and opposite reaction. A light bulb went off in Izuku's brain.

  My quirk negates Newton's third law. That's why the Robot can punch through my smoke so easily.

  "I've figured it out." He murmured.

  Aizawa raised an eyebrow.

  "Figured what out problem child?" He asked. Izuku couldn't see it, but the man was smiling.

  "My quirk. It negates Newton's third law of motion. That's why you and the robot could smash through my solidified smoke so easily. You didn't receive an equal amount of force in return. My general strength with my quirk has been getting stronger, that's why you've needed more force every time to break the walls. But.. if I were to mimic the effects of Newton's third law with my quirk.."

  Izuku pressed a button on his suit, letting the smoke contained there jettison out through the exhaust pipes.

  The smoke moved around the room, permeating the cracks in the walls, floor and ceiling. With a single thought, the smoke hardened, securing the room perfectly. He didn't need to focus on shaping the smoke, the contours of the cracks did that for him.

  Slowly and carefully, Izuku walked across the room, picked up the dummy, and brought it back to the two heroes.

  Aizawa was grinning.

  "Congratulations kid. You've just graduated to shape training."

___

  The rest of the lesson with Thirteen was very informative. The hero enthusiastically taught him what to look for in unstable infrastructure, how to tell if something was load bearing, and other useful tips about rescue work in an unstable building.

  Izuku would have one Rescue lesson a week, moving to a new zone in a repeating loop completing mock rescue missions that became gradually more and more complex and risky.

  In the meantime, the training sessions with Aizawa had gotten harder. The sports Festival was coming soon, and the man was working the teenager to the bone. He might have figured out how to make borderline indestructible 2D shields, but he couldn't do anything more than that.

  Simple spheres turned out lumpy, cubes were misshapen and rounded, and the less said about Izuku's 'pyramids' the better. Working in three dimensions was hard, and there was no missing law of physics to provide a shortcut this time. Practice was the only way. He could create the shapes just fine with smoke, it's just the moment he tried to solidify them he lost control over some part of it and it came out all wonky.

  On top of creating 3D structures, body training and classwork, Aizawa was also teaching Izuku basic hand to hand. How to throw a punch, how to take a punch, how to plant your feet so a gust of wind didn't blow you over. Izuku learned that Thursday that his little session of online martial arts learning was woefully inadequate.

  He was starting to appreciate the taste of fresh air the few times he wasn't eating sweaty training mat.

  He was getting better though. His shapes were less lumpy, although as fragile as his walls used to be. He was fitter, and had put on a decent amount of muscle. His hand to hand, while still terrible, was probably better than most first year's. Izuku, Aizawa found, was a very quick learner.

  Then, the day of the festival arrived.