WWolfe made plans for a Sidisi primer about 4 months ago, but we still don't have it yet. This will be the primer for Sidisi until then. I don't get why it's taking so long. What could you possibly have that's distracting you? Besides the kids... and the wife... and a job... and applying for school... and a couple other responsibilities that I don't have.

Besides all that, what's your excuse?

I built this deck about 10 minutes ago and I play-tested it for 5, so I'm pretty confident that I know this commander inside and out. Before you is a quality primer for explaining Sidisi, Brood Tyrant, and should be the go-to reference until a better one shows up.

>Gameplan

This is a zombie tribal deck. Your goal is to make zombies with Sidisi, and then overwhelm the board with them. So, first thing's first; get Sidisi out. I'm included high-quality mana ramp like Horn of Ramos, Leyline Prowler, and Sisay's Ring to facilitate this. Step 2: start using self-mill effects. This can either be incremental mill like Grindstone and Sultai Soothsayer, or it can be mass mill like Keening Stone and Leveler. Leveler doesn't have any glaring downsides. Build up that zombie army. Step 2.5: use reanimation effects to return cards you accidentally milled away. Stuff like Bond of Insight, Golgari Findbroker, and Raise Dead. Lastly, end the game with that massive token army. There are some good overrun effects like Decimator of the Provinces, and other buffs like Obelisk of Urd. Sure there are a lot of high-cost cards, but that's just to ensure that I'll be able to draw into one in the late game.

>Deck Strengths and Weaknesses

Perhaps this decks biggest strength is that it looks like it was built very quickly as a joke. And while that is true, you shouldn't underestimate it. Cards like Spiketail Drake, Silumgar Scavenger, and all of the taplands are designed to make people think this is a very weak deck. It's why there is also a low amount of card draw, tutors, and win-conditions; this deck is supposed to fly under the radar, and then strike in an explosive finish.

Unfortunately there are a lot of flaws here, but I can't help but feel that it's more of a problem with the commander than the deck. One problem is that this deck is susceptible to board-wipes. To mitigate this, I used less creatures than most Sidisi lists, which causes the deck to be less vulnerable to removal. I've also chosen to chose "worse" cards, that are lower priority for removal (Millstone instead of Mesmeric Orb, for example). It makes people less likely to target my permanents, which is fortunate, as I've included very little removal myself. The mana base is sometimes an issue, but I can't seem to find any good substitutes. What could be better than the card draw from Golgari Locket, or the scry from the temples? Arcane Signet doesn't draw cards, and Tropical Island doesn't scry. Nothing better has been printed yet.

>Single-Card Discussion

Deathcap Cultivator: Gives mana ramp, and makes for a good blocker.
Codex Shredder: A useful mill effect, and can be recursion.
Leveler: Mill your entire library and get 27 zombie tokens, then win the game. That's how this works right?
Back from the Brink: Amazing recursion card that is definitely not over-costed.
Graveshifter: Recursion, that's a zombie as a bonus.
Reassembling Skeleton: A chump blocker every turn. The only downside is that it's not a zombie.
Geralf's Masterpiece: Who doesn't want a 7/7 with flying that can return itself? You weren't going to use those 3 cards anyway.
Josu Vess, Lich Knight: Yeah it's a lot of mana, but all of those zombie tokens are worth it.
Maggot Carrier: Name a better 1-mana zombie. I'll wait.
Prized Amalgam: Returns to the battlefield when something else returns to the battlefield. It never happened during play-testing, but I'm sure it will at some point.
End-Raze Forerunners: I can't think of a better 8-mana creature that grants trample.
Bojuka Bog: Great card... nothing bad... exiling a grave is... Actually, no, screw this. Dropping the facade. Bojuka Bog is absolute garbage. This entire deck is garbage, and I'm willing to promote all of these cards as good for the sake of a joke, but not this one. It sucks.
Lake of the Dead: Even though there are only 3 swamps in this deck, when they do show up the mana this land provides is great.
Urborg: Swampwalk is annoying to go up against. This will take care of it.

>Notable Exclusions

Mesmeric Orb: This card makes people angry. Even though it's widely regarded as the best mill card, it's useless if it gets removed, so why depend on it? I'll just use Cathartic Adept instead.
Undead Warchief: While the buff and discount is nice, why would I pay 4 mana when Obelisk of Urd can cost zero?
Underrealm Lich: No good against exile effects. Chronic Flooding works just as well.
World Shaper: I got to wait for this creature to die before getting all my lands back? No thanks, I'll go with Wilderness Reclamation for instant satisfaction.
The Scarab God: Sure, being a creature is good for Sidisi, and sure, the ability to recur any creature permanently and at instant-speed is pretty good, and sure, he's able to dodge creature removal pretty well, but isn't it better to just not be removed in the first place? Artifact removal is less common than creature removal, so Whip of Erebos is better.
Muldrotha, the Gravetide: High-priority removal target, unlikely that she last more than one turn. For that reason, Golgari Findbroker will work just as well, for 2 less mana.