See I bought a used Platinum Version the other day and along with all the Pokemon I could ask for (Darkrai, Arceus, ect.) alot of the pokemon had pokerus and it I sent them over to my SS game where I am currently raising my competitive team, and all my pokemon that I am raising got infected with Pokerus.
I had also noticed that this person had a level 100 shiny Metagross with a Pokerus, and all of its stats were at the maximum like every stat was EV'd. So yeah that's why I am so into the pokerus right now!
Thanks all for the help, I can't tell you how much I appreciate it!