Ok, I've tired to make up some description fast, so anyone who will grab this deck can play it relatively good.

The PLAN:

Try to play as aggro with zombies (beside Cryptbreaker, who has a lot more to offer than being tapped for attack) - if they eventually die, you can cast Rally in opponents turn to use ETB effects of Wayfinder and Corpse Knight to kill opponent with the triggers.

Example play:

You are at 8 HP, opponent is at 10 HP. It is his turn. You have in graveyard:  2 wayward servants, 2 Champions of the perished and 2 Cryptbreakers. Opponent chooses to attack you with few 4/4 creatures. Before blockers step (so still in attack declaration step) when you have priority, you cast Rally with X=2, you bring to play aforementioned zombies simultaneously, and they trigger:

#1 Wayward servant - 5 drain triggers,  #2 Wayward servant - 5 drain triggers, #1 Champion - 5 +1/+1 triggers, #2 Champion - 5 +1/+1 triggers. So at this point, enemy looses 10 HP, you gain 10. You win. Even if they survive this, you can block with 6/6 champions and all other zombies (recommended, you want them to die on block, so they can return to graveyard, so Rally effect won't exile them), and you can STILL tap each three of them thanks to Crypt Breaker to draw additional cards.

Another tips:

• Rotten reunion is GREAT agains any deck that runs Flashback cards, Phoenixes, Blue Gearhulks, Kroxas or any other grave-reccuring cards. REMEMBER - when opponent chooses/targets a card from graveyard, you can cast Reunion to exile it. 

• Mutavault - can tap itself to change into 'zombie' so you can have greater value from: Dark Salvation or Liliana's minus ability.
  
  
• Cryptbreaker - powerfull engine. He can tap and pay 2 mana to discard a zombie for a better Rally, or discard that unneeded lands (you'll most likely won't need more than 6 lands in play. Even if the game is long, you can stop at 8 lands and keep rest for discarding or pokerfacing) He also can be tapped for draw the moment he hit the board, as there is no "tap" symbol on him to pay that ability.
• Dark Salvation - with ANY zombies on the board, you can choose for the X to be 0 - then Salvation is a 1 mana removal spell, which suprisingly - is very good.

Sideboarding:

BIG AGGRO

OK, what the hell is big aggro - it is any aggro deck that uses creatures with high thoughness - You'll most likely won't be able to overrun them with 2/2 zombies, but you can drain them out. Use all Stitcher's Suppliers, Lazotep, Token Zombies and drain zombies to block all incoming threats - your plan is to eventually fill graveyard and return them all for a kill described earlier. There is a catch - Ooze - he will eat up your stuff and grow with HP gain, so he must die the second he steps on battlefield.

Also take notice if opponent is running blue mana - you don't want to be contered with your finishing spell.

IN Citywide outburst, 3x Fatal Push, Lifebane zombie

OUT 2 thoughtseize, 2 rotten reunion, 1 any

SMALL AGGRO

Small aggro = White weenie, mono red decks and so on. Utizlies small creatures, which most likely will give you opportunity to trade - which is a GREAT advantage for WB zombies. You can suffer a lot from Rest in Peace (white), or other strange enchantments, so be prepared after sideboarding. Due to drain HP effects which are frequent in this deck, you'll most likely win easily with red decks.

IN: Crippling Fear (choose zombies, let rest die), Ritual of Soot (sure, your zombies will die as well, but if opponent flooded board better - you can clear the state and grab them from graveyard with next turn)

OUT: thoughtseize x2 - with fast aggro you do not want to pay that 2 life, 

CONTROL

Be afraid of white. White color's ability to exile cards is single biggest threat there is (well, in black there are Exticntion Events and Shadows Verdicts too). There is no 'best' way to avoid this. You can either go all-in and try to cast Rally when he tries to exile zombies, or play-it-safe, and hold few threats in a hand so you can snowball opponent. Trying to run-over fast will be most likely 'the way'.

Sideboarding is tough. It really depends what kind of control opp is playing.

IN: Go Blank x2 (honestly, not sure about it, but in most cases it works fine), 2x Fragmentize (to get rid of the cages, RIPs, and other), 1 Deafening Silence - knowing there can be only one play from opponent gives you a great Rally opportunities

OUT: 4x Dark Salvation - as this spell will be most likely used to generate tokens, 1-2x any zombie or Rotten Reunion - about latter, if opponent plays control that do not utilize graveyard at all, you can cut one or two reunions

COMBO

Well, if it is Lotus Field, or any other 'complicated' combo that just tries to engage and kill you in one turn, you just need to be quicker or remove his puzzles. Necromentia is also good against Niv-2Light decks, as you can remove Nivs or BringToLight.

IN: Necromentia, Deafening Silence, Go Blanks

OUT: Dark Salvations

For the moment that is all. Hope you'll enjoy being a necromancer. Say Hi to Lili from me. Happy games!

P.S. One last thing - Nantuko and Ghast are option to bring killing combo to the table. How it can work? You need 4 cards for it to work:

Liliana on the battlefield.

Nantuko husk in Play or Graveyard (given you have enough mana)

Wayward Servant in Play or Graveyard (given you have enough mana)

Shambling Ghast in Play or Graveyard (given you have enough mana)

Example:

Liliana and husk is in play. it is your turn and you have 4 mana available. You -3 Liliana so you can cast zombies from graveyard. You put wayward servant in play, then Shambling Ghast in play (Wayward triggers, draining 1 HP).

Then you sacrifice Ghast to Nantuko Husk, husk is growing, Servant is generating 1 treasure on death. Since Liliana ability is active you can play Ghast again by sacrificing treasure. It cames into play, Wayward drains for one HP, you sac Ghast to Nantuko husk, create a trasure, sac treasure to recast Ghast and... you get the point, right? :)