Classic Phenax Mill
This is mainly a combo Deck that sometimes doesen't even need the commander to go off. playing it safe at the beginning with boardwipe and counterspells is key. In order to play this correctly you need to be ready to counter artifact hate, Exile Eldrazi Titans that will undo your milling, and not be afraid to mill yourself for card advantage. this deck also suffers from not having convenient artifact hate.
Killer Moves
Phenax + Eater of the Dead: Give eater the ability to mill, then exile creatures in graveyards to keep milling untill you can no longer hit creatures. This requires a certain amount of creatures in a graveyard, is a little clunky, and sometimes fails to completely annihilate in one turn. but if one person is running a creature heavy deck, its usually game over.
Duskmantle Guildmage + Mindcrank: Very easy to set up, once somebody loses life or mills, you kill all opponents, very hard.
Fraying Sanity + Traumatize/Fleet Swallower: Mill BOTH halves of someones library!
Phenax + Tree of Perdition: Not fatal but bringing someone down to 13 and then milling for 40-35 cards is very good for us.
Illusionist's Bracers + Aphetto Alchemist An apparent classic that I initially overlooked. This + Phenax, mills everyone completely. you don't even need phenax out yet, as this gives infinite mana so you can cast him, or even use that mana to counter a response. the Alchemist himself assists in ramp and mill so he is useful as well as deadly.
Gulitfeeder and the Guildmage can instantly kill with the right conditions.
Getting There
Demonic Tutor, Trinket mage, Dark Petition, Disciple of Deceit, Tezzeret, the Seeker.Tutors get our combo's. Trinket mage helps us get artifact lands, two very good mana rocks, Altar of the Brood and Relic is we are afraid of graveyard shenanigans. Tezzeret is as amazing as always, getting rocks, untapping them, getting combo piece's and sometimes overrunning an opponent foolish enough to let him remain on the battlefield. Disciple was practically made for this deck as it sets up reanimation and combos.
Big Ass Mill Men
Consuming aberration, Bonehoard, Wight of Precinct six, Nighthowler.These will mill opponents exponentially with Phenax, if you think an opponent may not have many creatures in their deck, mill yourself once to make them bigger and set up reanimation. these can also kill opponents with assistance from Rogue's passage. Consuming Aberration is scary, and if left unchecked WILL mill opponents quickly and occasionally Squish opponent's in one shot. Bonehoard works best if you have multiple creatures to juggle it around and is often very deadly. I played this deck for months and have never drawn into Nighthowler for some reason but it should work well.
Notable Mill Men
Manic scribe is a pleasant low drop that mills, do not be afraid to get out Phenax so you can mill yourself into Delirium. Undead alchemist is sometimes very stupid but needs help getting there. he combos pleasantly with altar of the Brood and gets disgusting if Intruder Alarm and phenax are out. Fleet Swallower is expensive but can be cheated out early. Jace's Archivist gives us extra cards, sets up reanimation, mills opponents, and ultimately infuriates our opponents. don't be afraid to get aggressive with his ability and Intruder alarm. Dreamborn Muse can feel bad sometimes but its usually worth playing. Jace is fairly weak and is better off using his first ability. He usually gets killed quickly and attracts unwanted attention, milling ten cards is not very good but people seem afraid of him for whatever reason.
Staying alive
Sheoldred helps pick off problematic creatures while using creatures in the graveyard to our advantage. Silumgar takes away bodies that are too deadly for us and Mirage Mirror allows us to take advantage of opponents permanents. I particularly like Imprison in the Moon as it presents a major problem when placed on a commander, Mono red decks sometimes crumple when this resolves. Faerie Artisans gives us a free blocker, steals and discourages EtB triggers, works well with altar of the brood, and makes milling creatures if you have Thousand year elixer. I love this card and it can even carry Whispering madness in a pinch! Coffin Queen is here primarily to discourage opponents that take advantage of being milled. It is best to keep her ready so you can fizzle your opponents reanimation attempts, or get rid of the unwelcome Eldrazi that undo's our milling progress. Most interactions with her end with the problematic creature being exiled. Did I mention she is cool AND sexy?
Reanimation
Beacon Brings back any creature we want plus our combo artifacts. Rise of the Dark Realms is usually game over.
Ramp
I hate that this color combination is restricted to mainly using mana rocks, as this deck can crumple to Aura of Silence, Vandalblast, and Stony Silence. Padeem sorta protects us from this but its not much. Inspiring Statuary has proven to be really good because it turns our low cost combos artifacts into mana! Mana Drain works too but it may attract the envy of our opponents.
Edit: This deck seems to anticipate creature based decks. Unfortunately, the players in my environment tend to play low creature counts and run enchantments, which makes things difficult. When you encounter this issue, it may be wiser to mill yourself as this deck has more creatures.
3/25/18 Added Necrotic Ooze, most of the creatures in this deck have game breaking abilities with Phenax, Ooze allows me to unexpectedly aquire those abilities through milling as well as gaining the occasional random helpful buff.