Nephalia Drownyard is arguably the most reliable of these cards since your opponent can't counter it or its ability. They can use Ghost Quarter on it, but no one's running Ghost Quarter , especially in three-color decks.

The deck feel a little "all over the place". I like some of the themes you're going for, but other than your counter/control setup, I don't see any reliability in the deck.

If Liliana of the Dark Realms is important to your strategy, I'd increase the number of them in the deck. I think Sever the Bloodline is more sideboard material than mainboard. Mutilate doesn't look strong in this deck, as you're only playing 9 swamps, and have no guarantee you're going to see a decent number of them, unless you have Lily out, which as a one of, isn't reliable. With 8 Counter Spells in your mainboard, I wouldn't be putting any in your sideboard. If anything, when sideboarding, you'll want to cut some of that counter magic out. Or, if you're going to have any counter magic in the sideboard, perhaps Dispel ? Homicidal Seclusion as a one of doesn't feel like it's going to help the deck at all -- all it takes is one Sundering Growth to ruin that entire plan.

Sign in Blood would probably be a good addition to the deck. Life loss won't be a big concern for you, as your goal is to control the board, and not give your opponent the ability to hurt you. Do you own any Snapcaster Mage s? I'd mainboard the Nephalia Drownyard -- you take out two basic lands to put those in, and they give you an advantage over the control mirror match in game one.

But, that's just my two cents.

Swap Think Twice for Ponder . It is WAY better.