i have done with the suggestions. I found here on how to evolve Misdreavus..but it didn't evolve when i used a dusk stone in HG.
Did you use it or GIVE IT. If you gave it then that is why it did not work. You must USE it on Misdreavus. If that does not work then there is only one explanation. Did you accidentally have it hold the Everstone? If so then that is why.