The Cecani siblings, together at last to raise an army like you've never seen. A heavy zombie tribal deck focused on creatures that don't stay down and spells to keep your opponents struggling while you flourish with possibilities.
Frequent things this deck does:
Rooftop Storm is your favorite card in this deck. It's your biggest instant game changer. You can dump all Zombies at all times, and you can cast any zombie from your graveyard for free with Gisa and Geralf. Combine that with an Ashes of the Fallen to cast any creature, or Havengul Lich can cast any zombie from your graveyard for 1. Or both for any graveyard creature for 1.
Sidisi, Undead Vizier is one of my favorite tutors for this deck. Enters, exploits self, retrieve either something you need or a way to retrieve from the graveyard and rinse and repeat. Combine it with the Rooftop Storm + Havengul Lich combo and you have a 1 mana tutor for anything. That's just ultimate value.
Gravecrawler is such a value zombie. He's the fuel for any death parade you want to lead. I would hardly recommend any zombie deck without one. Ghoulcaller Gisa, Grimgrin, Corpse-Born, Attrition, he does it all renewably.
Grimgrin, Corpse-Born. One of the scariest zombies in this deck. Combined with the previously mentioned Gravecrawler or any continual retrieval, he can be removal and heavy damage in one scary swing. However he is the basis for the only infinite in the deck as well. Combined with Gravecrawler + Rooftop Storm, you can infinitely sac and retrieve Gravecrawler for 0 and buff up Grimgrin, Corpse-Born. However it's the instant win if you have a Zombie death outlet like Diregraf Captain out with him.
Self-mill is highly recommended when you want to cycle to your power fast. Gisa and Geralf do it, Geralf's Mindcrusher can do the same if you'd like along with many others. Any zombie in your graveyard is equivalent to being in your hand with this deck. Any non-creature card is hard to return but if needed, there are ways to retrieve them with Codex Shredder, Perpetual Timepiece, or Possessed Skaab. When you want to get crazy with the self mill for maximum fun and shenanigans, Mirror-Mad Phantasm or Morality Shift are great gamechangers. Morality Shift is a dangerous card depending when you use it, but if you've got the Possessed Skaab still in your arsenal (aka not exiled yet), you can snag what you need and shift everything back.
Underrated Cards:
Phyrexian Crusader is a clutch creature I find myself reaching for more than I expected. An infect zombie with first strike who you can renewably bring back is such a nice creature to have. He's definitely a presence on the field who can't reliably be dealt with because of his protection.
Fleshbag Marauder, a 3 mana force sac. When you have retrieval, this adds a sac weapon to your renewable arsenal that is just a nice backup option when dealing with those few but mighty battlefields.
Gray Merchant of Asphodel, better known as Gary, may be one of the best black commons for any deck that causes ETB effects to trigger. You drain so much life while adding to your own survivability. Also "loses life" compared to "deals damage" is such a potent change when dealing with preventing damage. Gary can't be stopped!
Wonder helps with Zombies inherent weakness to flying. Very few corpses fly unless we're talking stitchwings. With your already self mill potential and sac outlets, it's not too hard to get Wonder in the graveyard. Once it's there, you have an army that flies so that's pretty neat.
Amulet of Vigor. You wouldn't expect much out of this artifact at first glance, but a LOT of zombies like entering tapped. (See Grimgrin, Corpse-Born, Army of the Damned, Geralf's Messenger, etc) So this just ends up being an advantage giver. Plus, your enemy has a card like Authority of the Council? Well, all your cards will be forced to enter tapped, then enter untapped thanks to the Amulet because of nice wording.
Urborg, Tomb of Yawgmoth + Zombie Master is a dirty combo that will quickly take enemies out if you have the horde to back it.
Drownyard Temple, the land that doesn't mind being milled. Quality.
Cyclonic Rift. I cannot stress the importance of this card. With B/U zombies, you don't have much non-creature based removal. You really don't. So this card is your bread and butter of life savers. Mass removal of artifacts/enchants giving you trouble, plus wiping their board in one swing. Usually a game ender in a card. And if you aren't able to end with it and need it again, Possessed Skaab has your back.
However Cyclonic Rift is assuming things didn't go your way. If you can, counter those pesky pillowfort denials and such with things like Counterspell and Countersquall. Perplex is a neat one because you can use it as a tutor for a 3 drop. And there are some pretty solid 3 drops you can snag: Death Baron, Liliana, the Last Hope, Phyrexian Crusader, Diregraf Captain for your infinites, the list goes one.
With these Zombies, the battlefield will usually go one of two ways: Graveyard arsenal or Horde mode. Either stack your graveyard with things that have graveyard effects (Wonder, Vengeful Pharaoh) and things that do well summoning consistently (Fleshbag Marauder, Gray Merchant of Asphodel, Sidisi, Undead Vizier), while having consistent creature revival (Gisa and Geralf, Havengul Lich, Sheoldred, Whispering One). That tends to be better for when you need to control the field and deal with pesky opponents. Or if you want raw strength to be the name of the game, go horde mode. Get some zombie spawners (Liliana, the Last Hope, Endless Ranks of the Dead, Army of the Damned, Grave Titan) and some zombie boosters (Undead Warchief, Death Baron, Diregraf Captain) and you'll be dominating in no time. Toss in a Zombie Master, Wonder, or The Scarab God and they won't last long with the horde around.
Zombies, always a fun deck to play. Whether you overwhelm the enemy or your own graveyard, zombies don't stay down. So have fun, cause an apocalypse, let loose. The dead don't judge.