Essential Mechanics of the Deck: Control/Removal; Mill; Heavy Damage.
Control (Kill):
Mutilate (with Watery Grave) for a lovely boardwipe if things get out of hand.
Murder to knock out creatures that could be a threat and add to the graveyard. Mostly to use to save a counterspell, or if I can't pull a counterspell..
Tragic Slip (Sideboard) is just a cheaper Murder, but slightly less effective.
Ultimate Price (Sideboard) has the same purpose as Tragic Slip, and the same drawback.
Control (Counters):
Essence Scatter to counter some creatures (mostly big creatures, but smaller if necessary. Helps me keep control of the board.
Psychic Strike is a nice counter because it lets me counter anything, and it lets me mill them a bit too. What more could I ask for?
Rewind let's me counter whatever I want, and let's me wind up for another go.
Syncopate let's me counter instants, sorceries, enchantments, or artifacts that could become a big nuisance. If something like Gravecrawler becomes a bother, then I can just be done with him. Also helps deal with Flashback.
Cancel (sideboard) just let's me shut down anything they throw at me, but it's a sideboard card, mainly because of it's cost.
Mill:
Consuming Aberration is a nice, big, scary monster that also lets me mill them to zip with every card I play. Definitely gives me a major advantage and is just a wincon in itself.
Mind Sculpt probably one of the best mill cards in the world.
Thought Scour card advantage and mill in one? Works for me!
Psychic Spiral is pretty much my second wind. If something goes wrong, this is how I get back on my feet. gives me back my Grimoire or discard fodder. also let's me mill them into oblivion.
Dream Twist is here for the flashback. I can discard it for my Grimoire and then I can pull out Flashback to mill them out some more.
Creatures:
Consuming Aberration can become a monster by the time I pop him out. By the time he's on the field, he's a lethal swing, if I play my cards right (get it?).
Lazav, Dimir Mastermind is a fun guy to have around. If I mill anything of theirs that I happen to like, I can get the benefits of that creature. Basically salt on the wound for creature-staple decks.
Jace's Phantasm is a fast blocker that can become really strong, really quick, which gives me a good defense for a time. Put out one or two and I should be good.
Key Card(s):
Grimoire of the Dead is pretty much the staple of the deck. I'll mill all of their creatures, kill the ones I can't counter, and then pull them back from the grave and swing for big. Pretty much spells game over for them unless they pull a miracle out of their sleeve.
Strategy: Control the board, get as many of their monsters in the grave as possible, and the pop the Grimoire of the Dead and swing for big next turn. I like the idea of this deck because I can either beat them to a pulp with creatures, or mill them to death.
And that's all, folks! Any and all suggestions are appreciated