Like my 100 mewtwo.Since it is lv.100 it couldn't gain EVs but could it get pokerus? (Note:It wouldn't have an effect on mewtwo but could it just be there for looks?)
Pokerus is a virus and affects all Pokemon, even if they don't need it. After this it will be cured and on a level 100 Pokemon it is preety much does an accesory