In an attempt to steer this back from Petrice and Elthina (as much as I like to talk about them) to mages, I'd like to say that of DA2s anatagonists Petrice, Meredith (even despite the idol) and the Arishok were probably the ones best executed. They get plenty of screen time, we get to see them develop and we get to explore their characters.
This is something the mage antagonists of the game lack. Most are one-shot villains, often of the cardboard variety. I like Grace, but I think she could've been so much better done. The idea of a mage getting consumed by desires of revenge and valuing it far over freedom, enough to derail a coup, is not a bad one. But it lacked... among other things... we never truly saw her descend into that (whereas Petrice absolutely had progression).
Orsino is only a true antagonist for like 5 minutes. Prior to that he's actually seemingly innocent. He more or less comes out of nowhere, unlike Meredith who dorectly or indirectly had her presence felt from act 1.
Of all the mage antagonists, I'd say only Anders is well done. And even then, it's debatable if he's an antagonist at all.
SO here's to hoping we'll get more mage anatagonists and that this time, they're far more interesting than DA2's variants. More like Petrice, Arishok or Meredith. People that'll earn our emnity, respect and/or sympathy.