My deck started out a lot like this. A little bit of mill, some forced draw and discard pieces and a pinch of reanimation. I gradually streamlined towards a combo deck and eventually changing the commander toOona, Queen of the Fae. This looks pretty fun to play but a bit too slow for multiplayer.

Are you against infinite loops? If not, Mindcrank and Bloodchief Ascension deserve a slot here. I'd also get rid of the tap lands, Crypt of Agadeem, Nephalia Drownyard Deserted Temple and Thespian's Stage and go with more fetches.

Phyrexian Arena is nice but Monastery Siege and Necropotence sound like better options to me.

Consecrated Sphinx is another card you might want to consider putting in the deck as well as cards like Traumatize and Hinder (for you Tunnel Vision).

Thank you so much Megalomania!

I agree on all your points, to be honest this is my wife's deck where both the theme (Mill), Commander (She loves the look on my face when it hits), and Colors (Dimir). This great and all but I have no experience with any of those things other then dueling her when Esper control was a thing (and getting my ass handed to me). As you can see some of those things are in this deck (thanks for reminding me of Consecrated Sphinx)

I only have a small amount of the cards that I have already for this which makes all your changes welcome and very possible. Being that this will be her permanent Commander deck I've been hunting for foils of known staples of this deck getting them using my tourney winnings. Any more changes would be greatly appreciated.

Glad to help. If you guys are playing one on one, you might want to look at my Lazav duel commander deck Lazav: Dimir Blitzkreig. It's a completely different concept from yours but it has been working very well for me.

Looks like there this will be build for Multiplayer on request with a separate list for 1v1. We were looking at this thread here for alot of good ideas that match what she wants to do. Shares alot of card picks.

http://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/216749-wrexial-mesmer-of-the-deep-fate-reforged-set

Well I have finished majority of the Deck now, only missing a few things to make it awesome. (See Sideboard).

I'm going to do a clean up of the deck here soon to make it more presentable, but happy wife is happy life.

I'd look at stealing Planeswalkers. Dragonlord Silumgar

I noticed you don't have the infinite combo of Bloodchief Ascension + Mindcrank . I personally have this for any mill deck I make especially for life gain if you play more then 1 other player.

Mindcrank is in the Acquireboard, so it will be and should be in the list. However Bloodchief Ascension in my meta is just a dead draw. Others that use it have had it sit until it's at 2 counters, but once it even threatens to go to 3 it'll be destroyed. It's way too obvious when it's played what it's going to do and really becomes nothing more then a target. I don't see the value of it when there are so many other ways Mindcrank can be awesome.

I'd drop Codex Shredder for Altar of the Brood because it is more effective in a multiplayer game, can be activated more than once a turn,and it has a better interaction with some other cards (such as Undead Alchemist).

Thassa, God of the Sea is also invaluable in the 99. She lets the big guys in and she does an okay job of filtering draws. What do you use Necrotic ooze with, out of curiosity. I never found much to use him with in a deck like this.Usually he collects useless abilities from my opponents' creatures.

Guiltfeeder can be a really intimidating creature in a mill deck like this.

How often do your big creatures get killed before you can use them, like your Aberration or a Nighthowler? I really like Altar of Dementia as a response to boardwipes. It's a nice way to say "F-you" to the person who kills your things, plus you can sac them when they become blocked to make sure your opponent has something to remember them by.

I really like the deck. You made a lot of really nice choices. I just thought I'd share a couple of the things that I like in my deck.

I really like Altar of the Brood my wife somewhat likes it, but with so many cards to get in, I replaced the Codex Shredder with something I had first. I'm really thinking of putting it in the acquireboard, but we both feel it's not as good as those already there and hard to put main deck. We will have to think on it.

Thassa, God of the Sea has what it does already in many other cards in the 99 but better is true. However my early game to midgame is to not seem to be a threat, dropping it for card advantage paints a different picture then what this deck wants to do.

Guiltfeeder is a need enough said for me, sadly though my wife doesn't see what value it could have compared to other cards we have

Altar of Dementia I'll have to look at, however like I said above we need to seem innocent as long as possible.

An option to do with a mill deck in replacement of vampiric tutor as an option is Scheming Symmetry, mainly as giving your opponent a card on top of their deck isn't going to matter if you mill it. Also works with archive trap for a turn one 13 cards milled.

Also Nightveil Specter fits well.