After being told of the mission he is going to be on, Izuku decided to do a little personal digging into the Shie Hassaikai as well as the villain Overhaul. As such, he grabbed something he wanted to show his father as well as something nice to give him and some of his more favorable members of the League. He also explained to Himiko that he was going to talk to his father and explained that this was a personal matter to avoid significant questions. She agreed and let him go, allowing Izuku to open a portal. When he stepped into the bar, he noticed Shigaraki on the floor with Stain atop him trying to cut his head off.

"You having some problems there, handyman?"

"Fuck you."

"Jeez. And here I was about ready to help you take a psychopath off you before he was gonna kill you. Now that you said that, go for his balls first, Stain."

Not knowing who Izuku was, Stain held one of his blades out to Izuku's face demanding answers. "Who are you kid? What business do you have here-" The Hero Killer was cut short by a force crushing in on his throat, the slayer of heroes drops both weapons and frantically clasps at his neck for air.

"He's quite the rude one isn't he. As for you, Hero Killer. I'm the most powerful being on the fucking planet. And you best remember that before you go threatening people you just met. You never know who's going to turn you inside out, asshole first." Tightening his grip slightly before slamming the Stain into the wall he releases the force choke on the villain causing him to cough violently as he tries to recover air. "Now, Tenko, is Father in? I need to speak to him about a matter of importance."

"Fuck you."

"You're bothersome. Kurogiri, is Dad here?"

"Yes he's in his office practicing on the pipe organ again." The wispy disciple of All for One replies with a slight bow to the son of the boss.

"Thank you. See that Tenko, was it that hard to say yes?"

"I hate you. I hate you both."

"Nothing like a loving family reunion to welcome you to your former home away from home. Stain. As you were and remember, go for the junk first." Izuku responds before floating up the staircase towards a closet with a perpetual vile gray viscous sludge portal. "I'm going to need a new change of clothes." Izuku murmurs as he walks through the portal.

Begrudgingly walking through the portal of gray sludge, Izuku sees his father playing a gothic pipe organ that would normally be from a church, had it not been under the effect of a reality warping quirk, easily taking up the majority of a cathedral. The gentle sounds of a reminiscent melody dancing across the keys. However as Izuku approaches, his Father changes keys and becomes more aggressive upon dancing his fingers and tendrils across the keyboards playing the Ballad of Davy Jones.

https://youtu.be/D-_qS_3KXBA

 Izuku stands patiently off to the side as his father conducts the recital to himself waiting for him to finish playing the organ. The pipe organ itself has been shrunken down to a solid black double keyboarded grand piano in appearance.

"Ah, Izuku. How have you been my boy? I saw your fiasco in the Sports Festival the day before and I must say, quite a way to go out." Hisashi greets as he brings down the cover over the keys. He uses a tendril to close the open portion above the pipes before turning to face Izuku.

"Why thank you. I thought it was a fun way to go too. I thought it was something to help that General Studies guy who by the way, is now my classmate. Plus I managed to get a thorn out of me and the girls' sides." Izuku explains manifesting a black throne behind himself and his Father as they begin to converse. As they speak, two old fashions levitate over from the private bar, finding their place in each All for One user's open and expectant hands.

"I'm guessing his place in the Sports Festival had a role in it?" Izuku smiled while nodding. "Such hypocrites the Hero Board are for not allowing someone with such an amazing quirk in the Hero Course. If I had a quirk like that, taking over the world would be as easy as playing this organ right now."

"Says the man playing with tendrils and with braille on the keys so that you can read the notes.." The two looked to see AFO still having his tendrils out from the act as well as bumps where on the center of the ivory keys themselves. "Anyway, I came here to ask you for help with something and to show you something."

"And what, praytell would those be? Is it something involving hero work?"

"Technically speaking for one yes, however it's something up your alley from back when we pulled heists. Assassination of the head of the Yakuza at this time."

"You have my attention, however what is the second thing you mentioned?" Izuku pulled out both sonograms to give his Father, the old All for One user reverts his form to a younger self with eyes, now almost identical to his son across from him he studies the two sonograms he had been given. "I've long awaited this day. Who's sonogram is this?" The old man says in a jovial tone pointing to the larger male developing infant on the picture in his right hand.

"Rumi Usagiyama. AKA, Miruko." Izuku answers.

"A connoisseur of powers and powerful women. The apple doesn't fall far from the tree. Oh! And look here! There's two little beans in this one. I bet they'll be a powerful and deadly set of twins when they're of age." All for One says excitedly looking at the early stage sonogram of a set of twins.

"Those are my children with Todoroki Shoko, it's too early to tell their sexes yet but Shoko wants a girl and a boy." Izuku responds as his father quickly grabs two empty frames he had on a table nearby before mounting both sonograms on the wall.

"You've made me very happy, my boy. I'm going to have All the grandchildren. Now as for your question involving that particularly bothersome Yakuza, I have more than information. I have locations, faces, goals and research as well as evidence on them. I will give you this but there's business to be had first my son. You know these things."

"I completely agree. How about this, once I have Overhaul's head on a spike I'll "confiscate" any research they have into quirk behaviors and predictions as well as any funding I find. As for me, I want to know everything that you do about the Shie Hissaikai." Izuku responds, laying out the terms of the agreement.

"You've gotten very adept at persuasion and the art of business. I accept these terms. Now let's begin. Their former leader is dead so he's of no use. However, they're now under the control of a mentally deranged lunatic known as Chisaki Kai, how pretentious to call yourself god like he does, but you were already aware of that." Hiashi pauses to take a sip of the near masterfully crafted spirit in his hand. "What you and the heroes don't know is what he is planning on doing with the research that they're conducting. You're more than an expert in powerful reality warping quirks owning a few yourself yes? But what about one to turn back the sands of time? To rewind anything to a previous age like the push of a button on a television remote. Kai Chisaki is harboring an abducted 2 year old child named Eri. She has no surname. Her quirk let's her do what I had mentioned and that madman is using her as a human guinea pig for his experiments into creating 'The cure of Man.' a device or drug more likely that can permanently erase the intended target's ability to use their quirks."

"Alright let me start taking notes. Crimes against Humanity, Human Experimentation." Izuku says out loud as he writes this down using a telekinesis quirk.

"There are 10 members of his subordinates that are facilitating the funding, extraditing and distribution of the quirk drugs that they are producing in secret. Below them are the scientists that work with the faction and the grunt muscle workers. Most of them: thugs, rapists. The type you like to tear the quirks out of. As for the location, I am supposed to be meeting them in an undisclosed location somewhere in Hokkaido in five days. From there their muscle, Kendo Rappa, will escort me to a meeting with their leader. In attendance for that, I was told that Overhaul, his financial advisor Mimic and his assistant Chrono will be there. In the facility will also be his top brass known as the 8 Precepts of Death. Rappa as I mentioned before, Shin Nemoto, Rikiya Katsukame, Toya Setsuno, Yu Hojo, Soramitsu Tabe, Hekiji Tengai and Deidoro Sakaki. Since this is more because of fear of what I am capable of, they are not taking chances."

"And the girl? Where is Eri going to be during all of this?"

"My best guess will be somewhere where Overhaul doesn't have to worry about her escaping. Hidden room perhaps. Maybe in the lab itself. Even though I've done horrible things in the past, I'm not personally a fan of torturing a child without that child actually causing bodily harm or attempting to do so to me. So if you ask me, I'm more than happy to help where I can to take this monster down. And that's coming from Me of all people, it's not everyday you earn the title of The Blight of Man you know."

Unsure what he's seen, Izuku asks. "What do you know about the experimentation being done on her?"

"I think it's best if you drink the rest of your spirits first. Because what you're about to see will make you want to rip apart every single member of the Shie Hissaikai limb from limb. I took in the children that I found abandoned. I may be evil but there are limits to even my cruelty. Chisaki has no conscience, no regard for human life and is so evil that Satan himself looks like a saint in comparison." The old villain watches as his son chugs the rest of the spirit he had before motioning to a computer display opposite them.

The events that Izuku had witnessed the Shie Hissaikai commit to an innocent toddler were so horrid that both authors have agreed not to give the details of the experimentation. What we can say is that the unbridled burning fury that Izuku was experiencing is near indescribable. Vowing that at the end of this raid, Overhaul will suffer as he's made Eri suffer. For as long as his deeds warrant. Using one of his quirks, Izuku copies the evidence that he was shown onto a quirk data drive and warps it directly to the office of Nighteye with a note attached to the device. A single note that asks one question. "Am I allowed to violate the Geneva Convention? What is enclosed on the drive is the worst crimes against humanity that have ever been committed against a single child. My recommendation is that All members of the Shie Hissaikai be killed on sight."

"The only reason I haven't waltzed down there and brutally slaughtered them like beasts is the Deleter rounds. I'm afraid that I am not immune to those effects and If I were to be struck, they would erase not only my quirk but the quirks I require to simply remain alive. I have my own terms to our agreement. You go down there masquerading as myself and you kill each and every member of that organization. Show no mercy and bring me back the head of Overhaul before you bring what's left of him to the WHA and whoever is your superiors. I'm going to give you my suit and helmet to masquerade as me and infiltrate the facility. There when you're in front of Overhaul. You can enact your justice and Eri's vengeance."

Izuku smirks before answering. "Alright. Just so you know, Overhaul's death isn't gonna be quick. Oh no, it will be painful and make him know that the hell he put a small child through will be looked at as a blessing." He got up to begin heading out before stopping. "Oh and by the way, you may end up with another grandchild at the end of this. I'm going to take her in after the rescue." A smirk came on AFO's face as he turned back after finishing his drink, turning back to play the organ again.

"You have people to kill my friend. Happy Hunting." All for One grins as his younger face melts away into the scarred unholy visage that we all know and fear. 

And that finishes this chapter. See what happens next time with Izuku infiltrating the Hassaikai. Hope you all enjoyed and thanks for reading.