i have found that for each mono colored deck, All Is Dust is a staple. You might also want to try Karn Liberated , a great way to deal with Iona, Shield of Emeria .

I had hoped to use Voidstone Gargoyle Or Nevermore for problems like that, but maybe a Spine of Ish Sah . Would that work? Karn is a bit outside my price range.

On a related note: Runed Halo , Exclusion Ritual , Voidstone Gargoyle Or Nevermore ? They are all very similar but provide different advantages: Runed Halo makes everyone else come up with there own answer, Exclusion Ritual takes out a problem that already exists, Voidstone Gargoyle shuts off abilities, etc.. So Which one(s) should go in?

runed halo doesnt work, iona isnt targeting you, that colour is just blanket banned. Same with ritual, if iona names white you cant remove her, if she doesnt you dont care too much.