Hello all,
Quick disclaimer I'm working on an Oath list, so the sideboarding guide below might not be up to date.
The deck above helped me acquire a 10-4-1 record at GP Oakland. The deck is a blast to play, it's not overwhelmingly difficult, but it does require a lot of foresight on how a game is going to progress/what you typically want to be doing from a given board position. Mastery of the Unseen is easily the best card in the main deck against the majority of the field, and whatever you do - do not try to rebound a Part the Waterveil with Narset it doesn't work sadly. I hope you enjoy the deck, I'm very close to having a fine tuned list, but with Oath coming out next week it'll be back to the drawing board for a little while.
Sideboarding Guide
Abzan:
Out: 1x Renewal, 1x Archive, 2x Part the Waterveil, 1x Dromoka or 1x Ulamog
In: Mastery, 2x Tutelage, 2x Den Protector, 1x Negate (if they are heavy on walkers)
If my opponent is playing black and has seen only Dromoka or Ulamog, I like to take out the threat they saw and then play the other threat from the board. This way they'll name the wrong thing with infinite obliteration. Swap the pairs back for game 3 since they'll still be expecting you to be playing the pair they saw in game 2.
Esper:
Out: 1x Renewal, 1x Archive, 1x Vegetation, 1x Dig Through Time, 1x Ulamog, 1x Outburst, 2x Part the Waterveil
In: Mastery, 2x Tutelage, 2x Den Protector, 2x Negate, Dragonlord Dromoka, Dispel (on the play)
Jeskai Black:
Out: 2x Jace, 1x Renewal, 1x Part the Waterveil, 1x Dig Through Time, 1x Ugin (If you don't fear Mentor you can take out Outburst instead of Ugin)
In: 2x Negate, 2x Den Protector, Mastery, Dispel - if you see Kol. Command: 2x From Beyond & Ulamog (take out 2x Archive, and Dragonlord)
Atarka:
Out: 2x Jace, 2x Narset, 1x Dig Through Time 1x Archive, Ulamog
In: 2x Surge of Righteousness, 2x Negate, Dispel, Mastery, Dromoka
Ramp:
Out: 2x Narset, 1x Outburst, 1x Dromoka or Ugin
In: 2x Negate, Void Winnower, Ulamog (If you want you can take out two other things (mastery and an archive) for the From Beyonds. They're good if your opponent has hangarback walkers as well.)