Mairsil (Visual)

Creatures and Artifacts with activated abilities for the general to use
Untap self abilities (like Horseshoe Crab), again for the general to use. Cards that refer to themself do work properly with Mairsil (the name gets replaced with "Mairsil").
Clones act as extra ETB effects for Mairsil (you clone the general and just let the clone die)
Sakashima and Quicksilver Elemental are basically more copies of the general

Click here for a text version of this decklist
Click here for my EDH Commander decks

General (1):
Mairsil, the Pretender

Creatures (47):
Myr Propagator Myr Welder Phyrexian Devourer Retrofitter Foundry Soliton Soul of New Phyrexia Grenzo, Dungeon Warden Havengul Lich Mercurial Chemister Nin, the Pain Artist Niv-Mizzet, the Firemind Olivia Voldaren The Scarab God Avatar of Woe Crypt Rats Dark Impostor Shauku, Endbringer Geth, Lord of the Vault Minion of Leshrac Necrotic Ooze Pack Rat Pestilence Demon Skithiryx, the Blight Dragon Thrashing Wumpus Unliving Psychopath Visara the Dreadful AEtherling Arcanis the Omnipotent Argent Sphinx Galecaster Colossus Gigantoplasm Horseshoe Crab Mercurial Pretender Mirror-Mad Phantasm Morphling Quicksilver Elemental Sakashima the Impostor Sphinx of Magosi Crimson Mage Hateflayer Hoard-Smelter Dragon Kamahl, Pit Fighter Skyship Stalker Spikeshot Goblin Torchling Viashino Heretic Whip Sergeant

Spells (4):
Cauldron of Souls Helm of the Host Staff of Domination Strionic Resonator

Mana Acceleration (12):
Basalt Monolith Coveted Jewel Doubling Cube Dreamstone Hedron Hedron Archive Gilded Lotus Grim Monolith Khalni Gem Mana Vault Prismatic Geoscope Pyramid of the Pantheon Thran Dynamo

Lands (36):
Underground Sea Badlands Volcanic Island Watery Grave Blood Crypt Steam Vents Sunken Hollow Smoldering Marsh Fetid Pools Canyon Slough Choked Estuary Foreboding Ruins Sunken Ruins Graven Cairns Cascade Bluffs Drowned Catacomb Dragonskull Summit Sulfur Falls Crumbling Necropolis Command Tower Path of Ancestry Reflecting Pool Spinerock Knoll Swamp Swamp Swamp Swamp Island Island Island Island Mountain Mountain Mountain Sol Ring Mana Crypt

Sideboard (Omitted/Cut card ideas):
Palladium Myr Eater of the Dead Blighted Bat Falkenrath Aristocrat Marchesa's Smuggler Jawbone Skulkin Rage Weaver Endbringer