If you just want to copy and take peoples' stuff Thalakos Deceiver might work.

Hey I'm running a similar deck theme wise: I Wanted One of Those! - Input Welcome!. And yours looks a lot better! Not to mention, you have given me a few ideas, Thanks! One that you may enjoy is playing Evil Twin, copy and removal win-win. +1

I was expecting to see Puppeteer Clique

The reason I'm not using Puppeteer Clique is you only get the creature for a single turn. Sure the creature gets exiled afterwards so your opponent can't use it either, but what's the fun in that?

Liliana Vess, in my experience, has always felt slow and awkward, so I removed it from my mill deck. I know that this isn't just a mill deck, it's about stealing, copying, and such. Have you considered Ashiok, Nightmare Weaver? While he exiles things, he makes for opportunities to steal creatures he exiles. Granted, he's a high target. Also, what do you think of Mindcrank, for its combo with Bloodchief Ascension as a win-con?

Liliana Vess is mainly in here for her -2 ability, although her ultimate can be great. I previously had Ashiok, Nightmare Weaver in the deck, but you had to constantly exile cards for him/her to be of any use, which kind of clashes with Lazav. Finally, I dislike using win-cons, and unless I search for them, the chances of me getting both Bloodchief Ascension and Mindcrank out at the same time aren't great, but I may include it anyways, as it isn't bad by itself.

I always have liked Ashiok, Nightmare Weaver and Psychic Intrusion for my own blue black deck, but I don't know what you should take out. Another card to try is Mercurial Pretender. I know you pulled Ashiok to run better with Lazav, Dimir Mastermind, but I have never found them to clash too much. Either way you get their creature, so I have never found a problem.

I noticed you have AEtherling spelt with the correct a+e thingy, but the site doesn't know that symbol. Use AEtherling as the name and it will go under creatures.

The thing is though, a lot of the cards in my deck rely on creatures being in a graveyard. If Ashiok just exiles them, the deck is just not as effective.

This is my Lazav deck that I've had a lot of fun with.

Whispersilk Cloak gives a creature shroud, which is n=better than the Prowler's helm.

Woebearer could be Phyrexian Reclamation which is easier to trigger.

More decent mill power for good mill chaos is Mesmeric Orb (simply the best in mill), as well as Dreamborn Muse and Memory Erosion

I would add more draw, like Visions of Beyond, Syphon Mind, Minds Aglow

I would cut either of Pongify or Rapid Hybridization for Reality Shift to get around Indestructible creatures.

Fool's Demise is good, but costly. I like Coffin Queen or Animate Dead.

I would cut Cryptoplasm for Dimir Guildmage and add in Mindcrank as a possible combo win.

Instead of either the Ring or the Portal, add in Sword of Body and Mind for more blockers, mill, protection, and damage.

Altar of the Brood is good mill that hits all opponents. It is also really good with Undead Alchemist

Cut Clone for Thassa, God of the Sea for more unblockability, which will help your Cipher cards hit more.

Hope this helps! Here's a +1 for building a fun Laazv build and reading this whole long post, haha. Happy milling

Oops, I meant Duskmantle Guildmage, not Dimir Guildmage...

Have you tried playtesting the deck yet? From the looks of it, you might need to do some streamlining. The deck seems to be putting almost equal efforts in copying, stealing and milling.

You have a lot of good cards in the deck but you need to make it a bit more cohesive and put some attention to how it should be progressing from early to mid to late game.

I actually have this deck in my possession, and use it often. It holds it own better when it is playing against multiple people, but it's still decent in 1v1.

I see you already have Sword of Body and Mind in the mabeyborad but I would recommend adding it main board because it works so well with Lazav.

It's only in the maybeboard because I can't afford it at the moment.

He man sweet deck +1, I was wondering if you could help me with a question, me and another user were arguing about weather double color cards like Nightveil Specter were legal in a mono black edh deck. Do you know if they are?

Sorry AbruptDecaay, but they are not. Otherwise I would have a lot more options.

Hey thank you very much for clarifying this, that's what I tryed to tell the guy but he thought I was lying to him.

"Maybeboard (182)"

...jesus. Need some help cutting?

Read the description, friend.

I'm surprised you didn't include Consuming Aberration. Pretty good in a mill-and-kill list, and it gets all huge real fast in multiplayer.

I'd have Consuming Aberration in here, but it just really wasn't doing anything, so I replaced it.

Consider Altar of Dementia along with Consuming Aberration and Sewer Nemesis and friends :)

Check out Jace's Vengeance by Immortalized, it's my main edh deck, and it may have some cards you find useful.