I thought about this deck from the first moment I saw the card of Mirri Maz Duur. The strategy is, of course, trying to apply the effect as often as possible and kill big guys of opponent. Greyjoy i think is the best partner house for Mirri since they have cards like The Kraken's Grasp for an unexpected win, or Fishing Net with wich you can avoid defense of Catelyn Stark or other big guys.
But only when i tested it I realized that there are much more combos that can make life difficult for the opponent. All the pillage, and the Reader effect to mill 3 cards, can help trigger Crone of Vaes Dothrak. Also you can use Magister Illyrio that works well with you character with renown, except that with Mirri. Not secondary, you have access even to The Seastone Chair. When you have both Chair and Mirri is very hard to stop a direct kill.
Finally, you have even Loot, that can erase the gold of opponent stopping every chance to counter your direct kill with cards like Treachery or Vengeance for Elia. And, you know, even if opponent countered it, you always spend his gold that is all you want ;)