UB Mill

[TheJord]

Mill deck using Memory Sluice and Megrim to kill.

// Lands
    3 [MOR] Mutavault
    3 [LRW] Vivid Creek
    3 [10E] Underground River
    4 [EVE] Twilight Mire
    4 [SHM] Sunken Ruins
    4 [SHM] Reflecting Pool

// Creatures
    3 [LRW] Liliana Vess
    4 [MOR] Oona's Blackguard
    4 [SHM] Cinderhaze Wretch
    2 [10E] Hypnotic Specter
    3 [SHM] Hollowsage

// Spells
    2 [SHM] Put Away
    4 [10E] Millstone
    4 [MOR] Mind Shatter
    2 [SHM] Tyrannize
    4 [10E] Megrim
    3 [SHM] Dream Salvage
    4 [SHM] Memory Sluice

Mill the deck with Memory Sluice and M'stone. Use Megrim to hurt them when they have to discard.

[SomeRandomDude]

What? No Traumatize? No Ambassador Laquatus? Cut the discarding thing, go full blown mill.

Broken Ambitions rocks massively. So does Howling Mine.

[FM]

I'm actually against using Howling Mine, since the opponent also benefits from it, and BEFORE you, at that. I'd advocate for Playing Jace Beleren, to the same effect. Other than that, I agree with NBarden, Ambassador Laquatus and Traumatize are necessary. 2 Traumatize, 3 tops, but 4 Laquatus for sure. And of course, you could get a bunch of stuff with cool abilities and play Rings of Brightheart, for starters, it doubles the effect of Liliana Vess (I'd play 1 copy, 2 tops) Jace AND Laquatus. I'd cut the discard theme completly as well, losing Megrim and other stuff like that, upping the count of Counterspells (playing Cancel, Rune Snag and Cryptic Command, for instance). I'd probably pack a Teachings package maindecked, as well.