I wanted to change things up after playing the Mimeoplasm for years since he came out, Sidisi adds a different kind of combo potential to the deck provided you have a reshuffle effect like an Eldrazi. With either Lightning Greaves/Cephalid Illusionist or Mesmeric Orb/Basalt Monolith, you can infinitely mill yourself to make an unending army of zombies! Those can either mill the opponents at instant speed with Altar of Dementia or just attack if you get a turn with them. If the combo plan doesn't work, you can function as a strong reanimator deck, with the potential for things like a turn 2 Jin-Gitaxias or Tidespout Tyrant. The deck draws inspiration from ThopterDepths - if the scary combo isn't happening, you have a powerful control plan.
Here's my list so far:
1 Bloodstained Mire
1 Breeding Pool
1 Cephalid Coliseum
1 Command Tower
1 Darkslick Shores
1 Drowned Catacomb
1 Dryad Arbor
1 Flooded Grove
4 Forest
1 Hinterland Harbor
2 Island
1 Llanowar Wastes
1 Misty Rainforest
1 Nephalia Drownyard
1 Opulent Palace
1 Overgrown Tomb
1 Polluted Delta
1 Reflecting Pool
1 Scalding Tarn
1 Strip Mine
4 Swamp
1 Temple of Deceit
1 Temple of Malady
1 Temple of Mystery
1 Watery Grave
1 Wooded Foothills
1 Woodland Cemetery
1 Yavimaya Coast
1 Acidic Slime
1 Birds of Paradise
1 Cephalid Illusionist
1 Deadeye Navigator
1 Deathrite Shaman
1 Deranged Assistant
1 Drift of Phantasms
1 Eternal Witness
1 Glen Elendra Archmage
1 Golgari Grave-Troll
1 Jin-Gitaxias, Core Augur
1 Kessig Cagebreakers
1 Lotus Cobra
1 Mirror-Mad Phantasm
1 Mulldrifter
1 Narcomoeba
1 Palinchron
1 Progenitor Mimic
1 Rune-Scarred Demon
1 Sakura-Tribe Elder
1 Shriekmaw
1 Snapcaster Mage
1 Terastodon
1 The Mimeoplasm
1 Tidespout Tyrant
1 Ulamog, the Infinite Gyre
1 Wood Elves
1 Jace, Memory Adept
1 Jace, the Mind Sculptor
1 Altar of Dementia
1 Basalt Monolith
1 Dimir Signet
1 Golgari Signet
1 Lightning Greaves
1 Mesmeric Orb
1 Simic Signet
1 Sol Ring
1 Buried Alive
1 Demonic Tutor
1 Dread Return
1 Exhume
1 Life // Death
1 Life from the Loam
1 Maelstrom Pulse
1 Mulch
1 Reanimate
1 Regrowth
1 Worm Harvest
1 Arcane Denial
1 Beast Within
1 Dimir Charm
1 Entomb
1 Force of Will
1 Muddle the Mixture
1 Pact of Negation
1 Sultai Charm
1 Vampiric Tutor
1 Oversold Cemetery
1 Phyrexian Arena
1 Sultai Ascendancy
1 Sylvan Library
1 Sidisi, Brood Tyrant