Biotron

When the outbreak hit Gotham too, things went to hell really fast: the pathogen was airborne and not very many were immune to it. The King of Gotham was among the first to get infected; Y/N though was one of the few lucky humans to avoid the irreversible mutation. That's why The Joker decided to use all his resources in order to save the only person that meant something to him: his daughter.
(also available on my masterlist)