Izuku Midoriya, Futa Virus

(All characters are 18+)

One for All was originally created when a stockpiling-power quirk was given to someone who could pass down quirks. Now, it's being passed down to Izuku Midoriya.

For his whole life, Izuku (and everyone around him) thought he was quirkless. He did have a quirk, but without One for All, it didn't actually do anything.

Now, as he consumed All Night's hair, One for All merged with and assimilated his quirk, empowering it. It was still mixing, and wouldn't make itself known immediately, but Izuku's quirk had transformed him into patient zero of a new infection- the Futa Virus.

Quirk Bestowal allowed the wielder to pass on quirks through consumption of DNA. When mixed with Izuku's latent quirk, this turned into the ability to give anyone who came into contact with Izuku's genetic material a large boost to their own quirk- along with a boost to their assets and libido. This new Futa Virus quirk would transform anyone it could into a powered-up, sexed-up hermaphrodite- starting with Izuku himself.