I'm still working out the sideboarding plans versus the major archetypes and trying to understand what the main weaknesses are in the maindeck. I've tried to include a lot of what has been working going into the rotation... additional sweepers versus energy, lifegain versus red, discard versus WU approach...
The spell/Tyrant plan on the high end catches a lot of decks off guard. The ability to hit an Approach on turn 5-6 catches even other Approach decks off guard. That lifegain really messes with the math that the aggro decks are doing, too.
Totally thinking about this too. Aiming at more of a token/huge zombies angle tho. Annointed procession and cast out in white. Growing rites of itlimoc, Lilly's mastery and then massive torments for the win. Almost have a decklist nailed down. I like adding approach as well.
Alright, so went 3-2 last night with the list. Lost 1 match after a 40 minute game against U/B control because I forgot I had Approach still in the deck, with game 3 going into turns. Lost another match against a Jund aggro list due to a misplay in game 1 (Didn't leave double White up for Settle the Wreckage on turn, as I had Shefet Monitor but no untapped white sources left) and keeping a shaky 6 that I never got a 4th land off of, as well as getting hit by double duress.
Anyway, thoughts on specific cards:
Lay Bare the Heart is a holdover from the previous non-ramp iteration of the deck. It's honestly not good enough. Going to take them out, and up the Duress count to 4 for future deck iterations. I might include 1-2 in the sideboard just to help against the Control matchup, but not sure on that.
Midnight Oil exceeded expectations, and hard. Another holdover from previous iterations, this card alone was the one that helped me remain in games I should have lost. I don't think you want 4 or even 3, but the time-stamp interaction does help a bit on the "downside", and by the time you have 0 cards you typically are playing off the top of your deck anyway. In the game where you want Midnight Oil, the downside is negligible but the upside is huge. In the game where you don't (Aggro decks), the game is typically over before it matters one way or the other. You are usually playing off the top of your deck at some point in the game, so this just gives you a way of burning through your deck. I seriously suggest this to anyone. This card kept me in games I had no business staying in.
Shefet Monitor is an all-star and needs to be in the deck. Uncounterable Ramp + Draw is worth 4 mana, as it means you can get to your relevant spells better.
Torment of Hailfire is going to be a 1-of moving forward. Generally, you always would rather have Approach as it just wins the game, but there are cases where you haven't case a single approach yet and an 11+ mana Torment wins the game on the spot. Still, 2 is far too many cards that just do nothing. Likely replacing the second copy with a third Approach.
Hour of Glory should just as well be a second Vraska's Contempt. It was largely because I couldn't find a second one. I feel having 2 is necessary against Red decks to buoy your life total a nudge, which is why Cast Out isn't realy a consideration. I did run into more times than I care to iterate where I Houred only for them to draw the relevant god the exact next turn. Such is life.
Wakening Sun's Avatar is just fantastic as a 2-of that people don't really anticipate after you fumigate them. It blocks Hazoret, and survives a lot of the removal being played. I had one in the sideboard that I am considering moving to the main. Might be a bit much to have that many high-end cards, however the consistency on getting it is nice.
Fumigate is great on turn 4. Probably going to need to add some more New Horizons to get there on a more consistent basis.
Sandwurm Convergence is cute, but slow and ultimately not worth it from what I experienced. It's being removed.
The mana bases is admittedly a mess. I'm likely going to increase the desert count simply because of how useful Ifnet Deadlands is.
Cards I'm considering for future iterations of the mainboard:
Overwhelming Splendor might be good enough to play. It does a lot more to various decks that Sandwurm Convergence, shuts off Gearhulks and Scarab God, and shuts off Energy based decks. Walking Balista might be too good of a mana dump to pass up. Scavenger Grounds might be just necessary to find a slot for, as it shuts off a lot of Control lines.
I had 4x Gifted Aetherborn in the sideboard that did nothing all night. The manabase is too shaky to get one consistently on turn 2, and I don't see a way to fix that. Consideration for replacement include Inspiring Cleric currently, however Authority of the Counsels is probably good enough to blunt the aggressive decks that I want Aetherborn for. I have 1x Settle the Wreckage in the Sideboard that comes in more than I care to admit. Don't think I want it in the main, however having 8-9 sweepers mainboard would help against creature based decks. Lost Legacy is downright necessary. You cannot beat Approach with this shell particularly well, and it helps immensely against Control lists if you follow a Duress with it. Also lets you snag Scarab Gods, which can beat you in the long game. Obviously, Carnage Tyrant wrecks control lists. I don't like it in the main due to the combination of sweepers + Scarab God, but maybe it's good enough.
On an aside, I've contemplated that Naya might be a good pivot for more aggressive metagames. While you lose Duress, Push, and Vraska's Contempt (With Torment of Hailfire being somewhat replaceable), you gain Lightning Strike, Abrade, a small energy package if you choose of Attune + Harnessed Lightning, Huatli, Warrior Poet could be good to produce endless bodies and gain life and you have Chandra, Torch of Defiance. You also get Chandra's Defeat out of the sideboard, which is just good living. You will have problems with Control in this shell, however, so 4x Carnage Tyrants is probably just necessary. Vance's Blasting Cannon is a consideration, as well for control. If you really wanted to, you could go a bit full-on Dino ramp with Burning Sun's Avatar, Carange Tyrant, Wakening Sun's Avatar, and 1x Gisharth. Is is good? Probably not. I think there are better ramp-lists for Naya. You also have Sweltering Suns.