cheating-is-good

Well, to answer a part of your question, Pokerus is a type of virus that your Pokemon can get infected with. While your Pokemon are infected with the Pokerus virus, they will gain twice the EV points that they normally would. This means that while infected with Pokerus, if your Pokemon grows up a level, their stats will increase two times then they normally would. So, in a way, they get twice as strong. It is a virus, but it is a really good virus. If you want to know if one of your Pokemon is infected with the Pokerus virus, then you should talk to a nurse at a Pokemon Center. She will tell you if a Pokemon is infected with Pokerus when she heals your Pokemon. It will go away with time, so don't do anything. Hope this helps.