General
1 Sen Triplets
Land
5 Plains
5 Island
3 Swamp
1 Underground Sea
1 Tundra
1 Godless Shrine
1 Hallowed Fountain
1 Watery Grave
1 Mystic Gate
1 Mistveil Plains
1 Orzhov Basilica
1 Azorius Chancery
1 Dimir Aqueduct
1 Arcane Sanctum
1 Petrified Field
1 Deserted Temple
1 Temple of the False God
1 Vesuva
1 Reliquary Tower
1 Mind Stone
1 Kjeldoran Outpost
Straight Up Fat
1 Exalted Angel
1 Battlegrace Angel
1 Dread
1 Magister Sphinx
1 Sphinx of the Steel Wind
1 Deep-Sea Kraken
1 Inkwell Leviathan
Draw/Filter/Tutor
1 Polluted Delta
1 Flooded Strand
1 Thawing Glaciers
1 Tolaria West
1 Soldevi Excavations
1 Sensei's Divining Top
1 Brainstorm
1 Enlightened Tutor
1 Vampiric Tutor
1 Demonic Tutor
1 Diabolic Intent
1 Journeyer's Kite
1 Courier's Capsule
1 Lim-Dûl's Vault
1 Mask of Riddles
1 Solemn Simulacrum
1 Covenant of Minds
1 Promise of Power
1 Mulldrifter
1 Eternal Dragon
Removal/Control
1 Condemn
1 Disenchant
1 Shred Memory
1 Hinder
1 Damnation
1 Spin into Myth
1 Moratorium Stone
1 Austere Command
1 Wasteland
1 Akroma's Vengeance
1 Archon of Justice
1 Identity Crisis
1 Duplicant
1 Hallowed Burial
1 Ethersworn Adjudicator
1 Helm of Possession
1 Swords to Plowshares
1 Venarian Glimmer
1 Necromancer's Covenant
1 Spinal Embrace
1 Ray of Command
1 Crib Swap
1 Angel of Despair
1 Cryptic Command
Recursion
1 Volrath's Stronghold
1 Academy Ruins
1 Reminisce
1 Sanctum Gargoyle
1 Twilight Shepherd
Utility
1 Lightning Greaves
1 Whispersilk Cloak
1 Wall of Denial
1 Paradox Haze
1 Esper Charm
1 Elspeth, Knight-Errant
1 Blatant Thievery
1 Kederekt Leviathan
Mini-Mill Theme
1 Mind Funeral
1 Nemesis of Reason
1 Extractor Demon
(Important: This has been copied from the origina Commander forum. This decklist is somewhat old and doesn't reflect the current deck.)
I have grouped the cards by broad categories. you will see cards like Soldevi Excavations under the Card Draw/Filter category and Necromancer's Covenant under the Removal section. I list them this way because that's how I usually play them.
There was a much larger Milling theme initially, but I found that if I wanted to say alive past the first few turns I has to include some additional control to dissuade opponents from attacking me. This was at the cost of cards like Alter of Dementia and Helm of Obedience. Plus, I didn't want to include a game ending combo.
Everything Sen is really a Goodstuff deck with some nice, subtle synergies. The trick with this deck is to allow the other players to go after one another and then take control mid to late game. You have to be very politically deft in order to downplay the threat from your Commander.