Slow, methodical, inevitable mill.
Mill gets a lot of hate nowadays. The main argument is that it doesn't do anything until you mill that last card. But the same argument can be said for damage or poison counters. I've won plenty of games sitting at 1 life or 9 poison counters. The other argument is that you need to mill at least ~50 cards. But mill cards are priced to scale with this; just like infect cards get a slightly higher cmc or are slightly less efficient, mill cards will usually mill for at least twice what a damage equivalent card would do.
Crypt Incursion is what really makes this deck viable in the competitive scene. Mind Grind is a late game finisher. If you prefer, you can run a 1-1 split of Mind Grind and Traumatize. Traumatize is very good early game, while Mind Grind gets better and better late game (more mana, and Traumatize becomes less effective). The high Planeswalker count helps buffer our life total.
Mainly Esper for access to Supreme Verdict. Sphinx's Revelation is nice, too.
Also considering a more aggressive version. A full set of Breaking // Entering and Crypt Incursion. Only really have trouble with aggro and black devotion (Gray Merchant). This should make the life gain faster from Crypt Incursion. Some removal would have to be dropped for this.
If you can stabilize against aggro, Crypt Incursion will win you the game. We only run 4 counters, so most Gray Merchants will resolve; however, Crypt Incursion helps against the inevitable Whip of Erebos.
Against control, the game is usually ours. These games usually run long anyway, and that only helps our wincon (as well as them drawing themselves to death). They will usually be able to out-counter us, but when they eventually drop their finisher, we should have enough kill spells to either burn through all their counters or actually remove it (more kill spells than open U mana when it comes to Aetherling). Pithing Needle shuts down Aetherling, Architect Jace, and Elspeth. Plenty of instant speed removal for Obzedat, Supreme Verdict or Far // Away for Blood Baron.
Being a creatureless control deck makes the control matchup much easier. Plus, we have a higher chance of milling their wincon than they do of drawing it!
I only splash white for Sphinx's Revelation and Supreme Verdict, but about half of my lands can tap for White, which is helps get a T4 Supreme Verdict. You want BB and WW early game for Supreme Verdict and Hero's Downfall, but only ever need UU for Daddy Jace and Sphinx's Rev.
To make it more budget, and a more reliable mana base, you can trade Oppurtunity for Sphinx's Rev and Aetherize / Whelming Wave for Supreme Verdict.
