Don't do drugs. Or Basilisk venom.

Sirius lay on the teacher's table and stared into the half-column, completely ignoring the confused gazes of his students. Oh, he knew perfectly well that he was as high as a kite, and that Ric would give him an antidote as soon as he asked, but it was too much fun for him to fuck the brains of his students.

"Black-sensei? Are you all right?" Asked Yaoyorozu Momo if he remembered correctly.

"Now is not Christmas. I wish it was Christmas, but this is not Christmas." Sirius jumped up from the table and turned to the blackboard. "Today is your first lesson in Tactics. I'm not going to toss you in boiling water with your bare ass as Aizawa or life will. I'm going to prepare you for any fucking snowmen who dare to annoy you."

Sirius began fanatically writing Runes on the board, feeling like Barty Crouch in a Moody disguise.

"Any decision you make while working as a Hero - Higher Powers, how I hate this name - can save hundreds of people, or kill hundreds of people. Therefore, I will teach you to think before you act. So that you don't end up in the grave before thirty."

He even made himself shadow eyes on the back of his head to watch his students' reactions. And look! Kaminari Denki decided to help him!

"I will also point you in the direction of the trash can if you can't find a place to dispose of the gum, Kaminari Denki!"

He certainly wasn't enjoying the way his hallucinations moved with the shocked students like waves, not at all.

"Does he have eyes on the back of his head?"

Sirius turned around and threw chalk at the blond's forehead - Black did not know that he had thrown chalk at the wrong blond - he did not have time to dodge.

"And ears in the right place!"

'What the fuck?!' Flashed through the heads of almost all students.

"Oi! The fuck are you doing?!" Bakugo growled, his hands sparkling with explosions.

"Education, my Padawan! If you can't dodge the chalk, how are you going to dodge the blows? CONSTANT VIGILANCE!" Sirius hit the table with enough force to crack it.

Midoriya, meanwhile, watched the show going on. He took the book from his bag and tossed it at Sirius's head. He caught her in the air and glared at the green-haired teenager.

"Coal for you then."

Suddenly, in one leap, Ric reached Sirius' neck and sank his fangs into it. The strange buzzing in his brain immediately disappeared, and he could think and see the world normally again.

Only Todoroki and Izuku did not look at him with a drooping jaw - the Broccoli boi honestly expected something like this and Shoto couldn't care less.

"Of course, ruin my fun, would you?" Sirius sighed and felt Godric crawl into his hair and hide there. "Okay, now that my deadly friend has provided me with an antidote to its venom, we can begin our lesson."

This knocked the students out of their stupor. Mina jumped up from her desk and pointed her finger at Sirius.

"What the hell was that?!"

"It was the effect of Godric's bite. If he didn't provide me with an antidote, or if I didn't force the venom out of my system sometime in the future, then I would've remained insane until my death. Of course, it would not have changed much in my life, but still. The madness of the Black family is enough for me."

Sirius turned and looked at the runes drawn on the board, his students were also interested in the incomprehensible symbols on the board. Midoriya knew they were runes, but he didn't know what they were supposed to do.

"What is that?" Kirishima asked.

"No idea, the structure is too chaotic to understand. Hell, if this works, then I'm a hidden genius."

Sirius copied the runes onto a piece of paper to show them to Luna and put the sheet in his pocket.

"Where is Aizawa-sensei?" Izuku said suddenly.

"Asleep, he threw you on me for today but it doesn't matter. As you already know, my name is Sirius Black. I will teach you the right thinking in stressful situations and tactics. But first, I want to hear what is most important in the Hero's work?"

"Breaking Villains."

"Communication with the media?"

"Power."

"The people around us."

Sirius snapped his fingers and turned on his heels.

"That. Once you become Heroes, your life is no longer yours. You must protect civilians from Villains, deadly accidents, natural disasters, and more. It doesn't matter why you decide to become a Hero, whether it's money," Uraraka blushed, "your ego," Bakugo sneered, "a desire to help others, or a desire to prove that you are better than someone else."

Sirius' gaze slid across the faces of his students.

"Remember, now each of you is one step closer to becoming Heroes. So your decisions will affect thousands if not millions of lives."

The classroom was quiet. Black knew it wasn't his best speech, but it was enough to make them think.

"Now, the heavy stuff is out of the way, who wants to see what happens when this chaotic shit on the board is activated?"

Sirius put his hand on the runes and ignored Izuku's screams to stop. The runes lit up with blue light for a couple of seconds and stopped, but nothing happened. Izuku breathed a sigh of relief and fell back into his chair - he didn't even know when he had time to get up from his seat.

"Holy fuck, if Luna saw what you did, she would've ripped your hands off. Seriously Black, do you have a death wish or something? This shit could've exploded in your face."

"Language! Heroes must keep their speech clean from such foul words!"

"Hey, is it snowing outside?"

Sirius looked out the window and his eyes widened in surprise. The winter was far away and the snow outside made no sense.

"Huh. Well, I think I got my Christmas?"

'Can I steal Aizawa's coffee for atmosphere? Yes, I can, just to say that venom is not completely out of my body if he complains.'

Sirius disappeared from the classroom only to reappear with a "definitely not stolen" cup of coffee. He drank from the mug and his face twisted like he'd bitten a lemon.

'Is this madman drinking cappuccino with caramel and pineapple juice? Jasmine, get me the fuck out of here.'

If Luna heard his thoughts, she would find it funny.

"Right, in our first lesson we won't be doing anything practical, so get your notebooks. I will be giving a very long and boring lecture on the terms used by Heroes for communication." The students groaned, even Izuku - he already knew this shit. "No whining or I'll have Midoriya shoot you in the knees."

Sirius waved his hand and leveled Bone Collector out of the hidden holster on Izuku's body and laid it on the table in front of the teenager. How broccoli could hide a fucking Smith & Wesson in his clothes, Sirius didn't know. He wasn't sure he wanted to know.

"Midoriya! How could you bring a firearm to school?!" Iida didn't jump up from his seat, but he looked like he really wanted to do it.

"It's better than leaving the fucking cannon at home where Karin can find it, or even worse - Eri." He grumbled and shoved the revolver back into the holster on his side. "Plus, I have a gun permit as a measure of self-defense, my Quirkless status surprisingly gives a couple of perks."

Sirius could literally hear Bakugo's teeth grinding.

'Hasn't Izuku talked about him before? Something about the old-school bully? Meh, let the kids beat each other half to death, if I could tolerate Draco, then Midoriya can tolerate the angry poodle.'

"Okay, we'll start by talking about the Hero names and why the fuck they are needed. The most obvious answer would be for working with media, but that's not all. . ."

Sirius talked about the need for Heroes to hide their identities, about how the names they choose later will be part of their lives. Gradually, he switched to soldier's/Hero's callouts and their meaning - even if some of the students already knew about it.

He continued to push information into the brain of the A-1 class until the bell rang, he immediately Apparated to the teachers' lounge to continue to annoy everyone and everyone who met him on the way.

---

Tohru couldn't understand why Black seemed so familiar to her. Of course, she saw him in the entrance exams - although half the time she looked at the huge snake near the entrance - and naturally, he was there for their Quirk-test-thingy. But it all seemed wrong. The invisible girl knew perfectly well that she had seen Sirius Black somewhere before. She just had to find out where.

And try not to look like a crazy stalker in the process. Yes, this is definitely an important point.

---

Izuku was about to shoot Sirius as soon as the bell rang. His friends immediately seemed to teleport to him and began to ask questions.

"Who's Eri?! Why didn't you talk about her?!" Mina shook him by the shoulders with THAT look in her eyes.

"Um. . . Midoriya, what did Black-sensei do to the weather?" Uraraka looked out into the street worriedly.

'That bastard forgot to deactivate the runes.'

"I don't have warm clothes, ribbit. . ."

"Midobro! Why do you need a revolver, you can kick ass without it!"

Izuku could only groan into his hands and wait for the next lesson. As he remembered, the next lesson would be Heroics 101 with All Might.

Izuku covered Mina's mouth with his hand, cutting off the flow of questions and stopping her. He sighed slowly and began to speak.

"Eri is Black's adopted daughter." He turned and looked at Ochako. "I don't know what exactly he did to the weather, most likely it has to do with the Runes on the board - I wouldn't touch them if I was you, Iida - and I don't need a revolver, this idiot just forgot it on the table a couple of days ago."

Izuku felt something wet on his palm and immediately let go of Mina's face. She just grinned smugly and folded her arms over her chest.

"That's what you get."

"Did you just..."

"Yep!"

Midoriya wiped his licked hand on her jacket.

"Gross."