This section is for commentary on each and every card in this decklist. It isn't necessary to read through all of it to understand how the deck works, but is useful when making changes to the deck so I know which pieces have multiple uses and which areas the deck can improve on.
P.S. It should be noted that all creatures in the deck automatically count towards triggering Sidisi, Brood Tyrant when milled, and near 33% creatures is desirable to maximise chances of triggering her each ETB/attack. Therefore some effects that may be found on spells are substituted with their creature equivalents.
P.P.S. It should also be noted that there are no basic lands due to inclusion of Hermit Druid.
Academy Ruins: A nonbasic land that gets Mesmeric Orb back after being milled because the Orb is so good. Not critical to the operation of the deck, and is an easy candidate for swapping for another utility land.
Aether Hub: An excellent land for mana fixing early. With the bouncelands, its second ability can be used multiple times.
Aphetto Alchemist: Part of the Mesmeric Orb combo. Also works great with Krosan Restorer, letting you untap 6 lands a turn.
Basalt Monolith: Part of the Mesmeric Orb combo. Also is just a good piece of artifact ramp. With multiple untap engines in the deck like Kiora's Follower, the Monolith is a good synergy piece.
Bayou: A nonbasic land that can be fetched with fetchlands.
Bojuka Bog: An important utility land in EDH. Gets extra value with bouncelands, and bring it back from the graveyard with Life from the Loam.
Breeding Pool: A nonbasic land that can be fetched with fetchlands.
Cabal Coffers: A powerful land in conjunction with Urborg, Tomb of Yawgmoth. Combined with untap engines can net insane amounts of mana each turn.
Chromatic Lantern: A powerful EDH staple that ramps while also fixing mana. Allows you to tap fetchlands for mana until ready to crack them.
Command Tower: Possibly the best "dualland" ever?!? EDH staple. 'Nough said.
Commander's Sphere: A mana rock which fixes and can be cashed in late game for a card. Very good when Mystical Tutoring for a counterspell.
Counterspell: A catch-all counterspell which is relatively easy to cast. (Could be replaced with another counterspell in the future.)
Craterhoof Behemoth: Ends games on the spot. A couple triggers off Sidisi, Brood Tyrant gives you a miniature army. Also counts all the untap dorks sitting on the battlefield. Almost never hardcasted; flash back Dread Return to catch people off guard.
Crop Rotation: A tutor for the powerful lands in the deck. Doesn't lose you any mana either.
Crucible of Worlds:Being able to play lands from the graveyard makes each Sidisi mill trigger basically into card draw. Basically. Makes opposing Wastelands targeting our Cradles and Coffers silly. Also can be tutored by Tezzeret.
Cyclonic Rift: EDH staple in any deck that can cast it.
Cryptbreaker:Card draw in the form of a creature (to help trigger Sidisi, Brood Tyrant's mill) that synergies well with the zombie sub-theme. Also a discard outlet in a pinch.
card:Darkmor Salvage: A "value" nonbasic land that helps get the self-milling started.
Dark Petition: A universal tutor which almost always has Spell Mastery turned on. Allows you to go ahead with producing ridiculous amounts of mana before you have Exsanguinate or Villainous Wealth in hand yet, as you can tutor for them afterwards.
Decree of Pain: An EDH staple that goes in any deck that can cast it.
Deep Analysis: Much needed card draw that gains value when milled.
Deserted Temple: A powerful nonbasic land in this deck. Another untap engine that nets you one extra mana with a bounceland (etc. Golgari Rot Farm) and nets you much more mana in conjunction with Cabal Coffers or Gaea's Cradle.
Devoted Druid: A crucial part of the Ooze Combo. Also works as ramp early game which can easily put itself in the grave without any effort when it is time to combo off.
Dig Through Time: One of the few card draw spell in the deck. This deck always wants to draw very specific cards though, so looking through 7 is better than drawing 3 (Treasure Cruise). Also with a full grave it always costs 2 mana in this deck.
Dimir Aqueduct: A nonbasic land which ensures land drops and can sometimes protect/reuse lands.
Dimir Signet: A mana rock that ramps and fixes mana.
Dread: A crucial card that ensure that you (almost) never deck yourself. Also gets you infinite zombies if desired with Mesmeric Orb + Sidisi, Brood Tyrant and Aphetto Alchemist/Basalt Monolith.
Dread Return: A reanimation spell crucial to the Ooze Combo. Allows the Hermit Combo to go off with nothing in hand or grave.
Dryad Arbor: A nonbasic land that triggers Sidisi, Brood Tyrant, counts towards both Cabal Coffers and Gaea's Cradle, and can attack in when pumped with Craterhoof Behemoth. In other words, super versatile.
Eternal Witness: Gets back anything from the grave you need.
Exsanguinate: A powerful card that ends games on the spot in a normal deck, and definitely in this deck which can produce insane amounts of mana. Is also notably the only life-gain card in the deck, so tutor for it wisely.
Fact or Fiction: A fun card draw spell that gives you choice over what you draw to complete the combo package you are building, and also allows you to dump a creature in the grave to trigger Sidisi, Brood Tyrant.
Fatestitcher: An untapper which can also be unearthed in a pinch to combo off with Hermit Druid on turn 2.
Filth: Powerful card which often makes you zombie horde unblockable, and lets Sidisi, Brood Tyrant get more attack triggers in safely. Always get it in the grave; don't cast it unnecessarily.
Flooded Grove: A nonbasic land that fixes mana.
Gaea's Cradle: A powerful nonbasic lands that synergies well with the zombie produced by Sidisi, Brood Tyrant.
Garruk Wildspeaker: One of the best untappers which ramps you and can pump the zombie horde for the win.
Glacial Chasm:With all the land tutors in the deck, this "utility" land can often give you the few extra turns needed to assemble some combo.
Golgari Rot Farm: A nonbasic land which ensures land drops and can sometimes protect/reuse lands.
Golgari Signet: A mana rock that ramps and fixes mana.
Hedron Crab: This creatures synergies well with fetchlands and gets as many triggers for Sidisi, Brood Tyrant as possible. Needless to say, filling the grave is a good thing.
Hermit Druid: An optional card that lets you usually win next turn. What's not to like?
Hero's Downfall: Excellent removal.
Kiora's Follower: An all-purpose untapper.
Kiora, Master of the Depths: Surprisingly, all 3 modes are great in this deck. If none of the power lands are out, -2 to try to trigger Sidisi, Brood Tyrant. +1 to untap Krosan Restorer and Cabal Coffers and swim in mana.
Krosan Restorer: Number 1 all-star untapper. Threshold is a joke to achieve in this deck. Super powerful and your opponents will likely target it within a turn.
Life from the Loam: A very powerful card which essentially tutors out the powerful lands slowly over time. Dredging helps trigger Sidisi, Brood Tyrant.
Lightning Greaves: EDH staple that protects Sidisi, Brood Tyrant. However, sometimes it is correct to equip it to Krosan Restorer instead or Necrotic Ooze.
Llanowar Wastes: A nonbasic land that fixes mana.
Mana Confluence: A nonbasic land that fixes mana.
Meekstone: This artifact keeps many aggro decks off your back while building up the first couple of turns. Easily tutored up with Tezzeret the Seeker , and doesn't affect our 2/2 zombies. (Perhaps more of a sideboard card, but in my meta aggro is everywhere.)
Mesmeric Orb: Hands down one of the best cards in the deck with Sidisi, Brood Tyrant out. Notice that it triggers separately on each untapping permanent, triggering Sidisi for EACH creature milled. If you got nothing going on in your hand or grave, tutor for this first and foremost. Added bonus if you mill your opponents out.
Mind Stone: A mana rock that cashes in for a card late game. Especially good when tutoring with Mystical Tutor when you need that card right away.
Misty Rainforest: Nonbasic land that fetches either shocklands or duallands.
Murderous Cut: Often to destroy any creature. Removal is king.
Mystical Tutor: A tutor used "surgically" for the right card at the right time (usually on opponent's end step). Early game get Life from the Loam, mid game get Splendid Reclamation, late game get Yawgmoth's Will or Villainous Wealth. When in trouble, get Toxic Deluge or any removal.
Narcomoeba: Basically a free creature for blocking flyers or saccing to Dread Return.
Necrotic Ooze: Essential part of the Ooze Combo. See explanation above.
Opulent Palace: A nonbasic land with all your colours. Possibly too slow coming in tapped, but so far hasn't been a problem.
Overgrown Tomb: A nonbasic land that can be fetched with fetchlands.
Pact of Negation: One of the best counterspells as this deck tends to tap out often.
Petrified Field:Nonbasic land that helps get those powerful lands back when we don't have Life from the Loam yet.
Polluted Delta: Nonbasic land that fetches either shocklands or duallands.
Prodigal Sorcerer: Essential part of the Ooze Combo.
Quillspike: Essential part of the Ooze Combo.
Reliquary Tower: A nonbasic land that gives you no maximum hand size. Sometimes annoying with too many combo pieces stuck in hand, but Rotting Rats comes in handy.
Rotting Rats: A useful card in letting us discard combo pieces, put dredge cards in the grave turn 2 while forcing opponents to discard, or unearthing to sac to Dread Return.
Scroll Rack: A powerful artifact that allows you to set up Sidisi, Brood Tyrant's next mill trigger as well as digging through the deck for answers/combo pieces super efficiently.
Sever the Bloodline: Exile removal that can be cast even if milled. (Also there is a powerful Omnath, Locus of Rage deck in my meta, where Sever works good against tokens.)
Sidisi, Brood Tyrant:"A benevolent dictator is better than a democracy." - Me
Silence the Believers: Exile removal that can have a lot of targets with all the mana you produce.
Simic Growth Chamber: A nonbasic land which ensures land drops and can sometimes protect/reuse lands.
Simic Signet: A mana rock that ramps and fixes mana.
Sol Ring: The best mana rock in all of Magic???
Snapcaster Mage:With the Mage in hand your entire graveyard is basically in your hand. Very versatile, letting your cast a milled Villainous Wealth late game, or reusing a Pact of Negation on an unsuspecting foe. Recursion is the name of the game when you're self-milling to victory.
Splendid Reclamation: This is ramp. Pure, unadulterated ramp. And the lands you're getting back aren't just basic lands either. What other card in Magic lets you get 10+ lands onto the battlefield for 4 mana?
Stinkweed Imp: Dredge is a powerful ability in this deck. Chose the Imp over Golgari Grave-Troll because the Imp is more impactful when hard-casted in a tight situation.
Strip Mine:Just because we're playing with Urborg, Tomb of Yawgmoth and Cabal Coffers doesn't mean we want others to do so too. EDH staple for spiky metas.
Sunken Ruins: A nonbasic land that fixes mana.
Sylvan Library: EDH card draw staple. Run in all decks that can cast it.
Temple of the False God: A nonbasic land that ramps.
Tezzeret the Seeker : A tutor for Mesmeric Orb, Meekstone, and Sol Ring.
The Gitrog Monster: A powerful creature with no combos but pure synergy. Drawing an extra card each turn and essentially each mill trigger. Always combine with a dredge card on the first upkeep trigger since you'll likely mill another land and still get the new card + the dredge card. Lets you run out Cabal Coffers and Urborg, Tomb of Yawgmoth in the same turn. Plus it just sits there as a fat deathtouch toad discouraging attacks while gaining you card advantage.
Thornling: Essential part of the Ooze Combo. I consider it better than Skithiryx, the Blight Dragon since it can grant the Ooze indestructible in response to removal. Also not bad on its own hard-casted.
Tolaria West: Tutors for a powerful land or Pact of Negation.
Toxic Deluge: An EDH staple run in every deck that can cast it.
Treasure Cruise: Often a sorcery speed Ancestral Recall.
Tropical Island: A nonbasic land that can be fetched with fetchlands.
Underground River: A nonbasic land that fixes mana.
Underground Sea: A nonbasic land that can be fetched with fetchlands.
Urborg, Tomb of Yawgmoth: A powerful land in conjunction with Cabal Coffers.
Vengeful Pharaoh: A super sneaky card that catches opponents off guard. It's so sneaky, I regularly forget its trigger myself. It isn't a may ability, but usually I realise at the end of the game that the Pharaoh was in the grave since turn 3 and I never remembered it :P Going back on top also helps trigger Sidisi, Brood Tyrant with a dredge card.
Verdant Catacombs: Nonbasic land that fetches either shocklands or duallands.
Victimize: A great reanimation spell with all the disposable 2/2 zombies hanging around. Lets you attack with Sidisi, Brood Tyrant because you actually prefer she gets blocked/dies so you can get an additional trigger reanimating her.
Villainous Wealth: A powerful (and fun) card to cast, usually with X>20 for maximum scooping effect.
Voyaging Satyr: A creature with the sole purpose of untapping the bouncelands, or better yet Gaea's Cradle/Cabal Coffers.
Watery Grave: A nonbasic land that can be fetched with fetchlands.
Yavimaya Coast: A nonbasic land that fixes mana.
Yawgmoth's Will:Very powerful spell that lets you cast your powerful spells even if they got milled without the hassle of returning Eternal Witness to grab the cards back, and much better than Snapcaster Mage since it gets all the cards you want (Protect that Exsanguinate with Pact of Negation hiding in the grave!) until end of turn. Just be careful not to cast it before trying the / engine with Basalt Monolith.