I always hoped I wouldn't get back into Magic. Sorry, wallet. My friends coerced me into playing again and introduced me to Commander. I went back and looked through my Onslaught-era cards from high school and my only potential Commander was Phage. Well, that's tricky. And I love tricky.
Part I: Getting Phage into play without committing suicide.
We have five main ways to get Phage into play. These are listed by priority:
1) Commander Beacon - this is by far the most optimal because (a) it doesn't put Phage's ETB lose condition on the stack, and (b) it costs zero extra mana to get Phage into the game. Grim Discovery and Crucible of Worlds are there to let you use it more than once.
2) Torpor Orb - it gets the job done, but it's going to get a lot of attention from opponents, and a well-timed artifact kill can leave you hanging with Phage's ETB lose condition on the stack.
3) Sundial of the Infinite - it gets the job done, but ending your turn means your opponents get a full turn to focus their attention on the very real threat of Phage being on the battlefield.
4) Platinum Angel - offers a way out, but is still susceptible to Phage's ETB lose condition stack shenanigans.
5) Withering Boon / Grim Discovery - Ugh. This is extremely inefficient and a waste of the Grim Discovery. This is your break glass in case of emergency option.
Part II: Building a hand to one-hit kill your opponent.
Much of the deck is focused around fetching cards to make everything in Part I work. But it also has the side effect of building combos can take out an opponent in a single turn. The combos are relatively easy to see. If we can bring Phage into play, equip her with haste (Haunted Cloak, Swiftfoot Boots) and make her unblockable (Shizo, Rogue's Passage, Whispersilk Cloak, etc.), we can one hit kill. Such combos cost a lot of mana, which is why we have Magus of the Coffers, Cabal Stronghold, and several fetch basic lands. Ideally, I'd love to throw the Cabal Coffers / Urborg land combo in there, but I want to play test this before spending $50 on two lands. Alternatively, we can cheese our way to victory with Endless Whispers just by summoning Phage (from any location), killing her, then sending her over to our opponent.
Part III: Surviving.
Everything else about this deck is built around surviving, controlling, fetching, drawing, and stalling. Phage takes awhile to set up. Nevertheless, she persisted.
Part IV: Sideboard.
Right now I'm just using the sideboard to tag cards that would noticeably improve this build. I don't own any of these, but if this deck works reasonably well I might treat myself at some point down the road. You know, if my friends still agree to play against this deck in a month and all.