Disclaimer I do not own My Hero Academia.
Nezu was doing paperwork while going over the hero course candidate list for the upcoming entrance exam. He smiled when he saw Hitoshi Shinso's name under regular exam and not under recommendation like All Might wanted. The 9th wielder was quickly proving he was a hard worker and very determined. After he was done with the hero course, he was going to check on the business students but then an idea struck him and pulled up Izumi Midoriya file. She had applied for general studies but people with any quirk that could heal others were quite rare, so he marked it as secondary and placed her in hero course. Even if she failed, he could convince Recovery Girl to train her and he could convince Izumi to be a paramedic at worst. In a few days the forms would go out and by then it would be too late to change it.
Nezu began to drink some tea when his email chimed. He opened it to find an email label Project Rhea, it had a marked as having an attachment and sender name was A concerned citizen. He was immediately suspicious and began running checks on it and found nothing. He opened it.
"Hello principal Nezu, I am a very concerned citizen and I believe you should be made aware of this information. Please note Project Rhea has encountered a heavy set back due to the intervention of the now deceased hero Smokewall and as such reached a conclusion that will not be favorable for its current condition. The members of Project Rhea have been bred with certain measures in place.
Protocol A: was the brainwashing of the subject to ensure loyalty to All for One.
Protocol B: was the recording and detailed note keeping of quirk linage.
Protocol C: was the elimination of former subjects and unnecessary offspring.
Nezu paled reading this information, it was cruel and meticulous something that All for One would do when no one was watching. He decided to keep reading, it was information after all.
Inside you will find a file on a member of Project Rhea who is currently on Japanese soil. This man is highly dangerous and is responsible for the death of 5 hero's.
Nezu clicked the file.
Elsewhere
"Robert I'm in" said the black male sitting at a computer.
"Good, Otto last chance I can go and make Nezu forget" said the old man.
"It's good, we want them to have a target and I volunteered, you guys have your positions and having the spotlight nowhere near will make it easier on you" said Otto.
Nezu's office.
Name: Otto Hans.
Allies: The pit, Mr. Clean, Kirby, Adephagia (see affiliations), Bone Cruncher, Clean up crew.
Age: 42
Blood type: 0+
Family: Unknown.
Affiliations: The Pantheon, Project Rhea, Ubel crime syndicate, The trashers.
(As a former member of the criminal organization Pantheon it was expected of all members to take names of a mythological god)
Quirk: Antibody.
Antibody makes the user immune to most poisons, diseases, and viruses, as well as an extendable jaw and a durable body that is resistant to most harm including their bodily fluids which can become acid.
Note: Nicknamed the clean up crew as this individual has used their quirk to dispose of evidence and witnesses. Last seen in a confrontation with the American Hero Smokewall.
Nezu googled Smokewall and found that he had been murdered nearly two years in America by unnamed blond haired male. He went back to the email and found another attachment labeled Project Rhea which he clicked on.
Some time ago an unknown man of science created the first man made quirk. All for One was greatly interested and began backing the man. The quirks were designed to seek out complementary quirks to evolve.
Project Rhea Experiment #5 Base Quirk Poison Resistance.
Upon release the Subject sought out a quirk called Iron Stomach.
Iron Stomach actually referred to all the organs on the inside of the body, excluded the skin, this caused the user to produce stronger antibodies and better resist infection.
The subject produced had a quirk called Improved Biological Resistance.
Protocol A was successful, Protocol B was successful, Protocol C was successful. It was unknown why but Subject left for Germany.
The I.B.R sought out a quirk called Hard Skin
Subject produced had skin that felt as hard as iron as well as the I.B.R.
Protocol A was successful, Protocol B was Successful, Protocol C successful.
Subject sought out a quirk called Consume All.
Consume All aloud the user to consume all organic and inorganic matter.
Subject produced mutated into a garbage disposal with acidic bodily fluids.
Protocol A was successful, Protocol B was Successful, Protocol C successful.
Subject sought out a quirk called buoyancy.
Buoyancy aloud the user to float in water and on air but combined with hardened skin aloud the user to regain to ability to swim.
Subject produced had a quirk called Iron Hyena.
Protocol A was successful, Protocol B was Successful, Protocol C successful.
Subject sought out a quirk called Enlarge.
Enlarge aloud the user to increase the size of a limb that contained bones.
Subject produced Quirk called Antibody.
Protocol A was successful, Protocol B was Successful, Protocol C successful.
Subject 5# was successful at neutralizing Subject 2#. It is unknown if subject has reproduced, and it is believed that is part of the reason he is in Japan however he could also be seeking out his former master as he is the last surviving member of project Rhea.
Nezu didn't like this at all for one he didn't know who sent him this and why and for another his tea was now cold. He would need to speak to All Might and the other top 10 to be on lookout for this man. He decided that he should get in contact with some retired hero's and see if they would be willing to help and while All Might wouldn't like, they would need more people to train his successor which meant a call to Gran Torino. They would need all the allies they could get if All for One was truly alive and had a monster like this in the world.