Legendary Pokémon

Hi I have been playing Pokemon forever, and well...what the HELL is PkRS????
I just got it to day on my Salamence, Gardevoir, Kirlia, Ralts, and Mightyena. I looked it up but realy got nothing that helps

I was also tolled that Joy can get rid of it but she never tolled me anyting. Help Please

In fact PkRs is something extremely rare and valuable. It is really useful, since it makes the EPs you would get after a battle DOUBLE. Don't get rid of it, it really helps with EV Training. You should keep at least one infected pokemon in the boxes, so as to infect the rest.