I think that Curator of Mysteries should also be kept as a 4 of, especially over Striped Riverwinder. I frequently found myself actually casting the card for 4 mana, and it really helps smooth out your draws. Another key factor is that once the deck starts working, Curator helps it continue to work by letting you more reliably chain cyclers. The consistency (and reach, since it does have flying) it adds to the deck is significantly more valuable than a 4/4 Hexproof.
Main deck Drake Haven is something I'd definitely consider if your local meta is predominantly slower decks. Also curious to hear how Shadowstorm Vizier works out. It's definitely something I considered, but it does require a bit of extra effort to make potent. Even though Vile Manifestation doesn't fly, it requires a lot less effort to make threatening and also cycles itself, making it an all-star in the deck. I'm definitely sticking to 4 Manifestations in the main, but I'm always interested in potentially powerful two-drops for the deck. Walk the Plank is something I'll have to try out as an alternative to Grasp of Darkness now that it's rotated. The fact that it's sorcery speed and can't kill Hazoret does make me sad though.
I'm definitely glad to see that discussion about this deck is continuing post-rotation!
From my initial testing, I'm not completely sold on Search for Azcanta in the main deck. In a game where you're not under pressure it definitely generates a lot of incremental value, but it's slow and the deck can't make incredibly good use out of the flip side given that it is primarily creature based (Although finding our artifacts is pretty nice). Against aggro or red decks, this is feels like one of the worst cards I can draw. I can see it in the sideboard for the longer, grindier match-ups, but I don't think at this time that it earns a spot in the main. Perhaps if aggro proves not as dominant this format.
I think another card that's worth discussing for the deck is Seekers' Squire. I've seen it in some of the Esper Gift decks, and it seems like a reasonable inclusion. It places a body on the board early, smooths out your draw, and can help fill up the graveyard. With an ability that triggers when it enters the battlefield, it's also a decent option to bring back with Gift. Playing a creature on turn two was often a key factor in a lot of games I've won with the deck, and it's part of the reason I still support the inclusion of Gifted Aetherborn despite its lack of synergy.
While I wasn't able to find all of the cards before the tournament, I managed to win my local Game Day yesterday 6-0 with a cobbled together version of the deck:
Round 1: Ramunap Red, 2-1
Round 2: Bant Planeswalkers, 2-1 (They ran both Cast Out and Angel of Sanctions, so the trick was not relying on the Gift plan)
Round 3: Mono-Black Eldrazi, 2-0 (This felt like a really good match-up. It helps when your two-drops can trade with Distended Mindbenders)
Round 4: Grixis God Control, 2-0
Round 5: Mono-Black Zombies, 2-1
Round 6: Ramunap Red, 2-1 (This was a finals rematch against the person I faced in Round 1)
This deck was really fun to play! Overall the only deck I really struggled against was Ramunap Red. A couple of the game wins I had against it were from my opponent drawing poorly, and I could have easily lost were luck not on my side. Flaying Tendrils helped a bit, especially since your two-drops survive it, but it definitely was not as good as I had hoped. Gifted Aetherborn was an absolute all star in nearly every match-up. In the future I think I'll actually try to complete the deck so I'm not running random one-of cards and to shore up the match-up against red.
Main deck Drake Haven is something I'd definitely consider if your local meta is predominantly slower decks. Also curious to hear how Shadowstorm Vizier works out. It's definitely something I considered, but it does require a bit of extra effort to make potent. Even though Vile Manifestation doesn't fly, it requires a lot less effort to make threatening and also cycles itself, making it an all-star in the deck. I'm definitely sticking to 4 Manifestations in the main, but I'm always interested in potentially powerful two-drops for the deck. Walk the Plank is something I'll have to try out as an alternative to Grasp of Darkness now that it's rotated. The fact that it's sorcery speed and can't kill Hazoret does make me sad though.
From my initial testing, I'm not completely sold on Search for Azcanta in the main deck. In a game where you're not under pressure it definitely generates a lot of incremental value, but it's slow and the deck can't make incredibly good use out of the flip side given that it is primarily creature based (Although finding our artifacts is pretty nice). Against aggro or red decks, this is feels like one of the worst cards I can draw. I can see it in the sideboard for the longer, grindier match-ups, but I don't think at this time that it earns a spot in the main. Perhaps if aggro proves not as dominant this format.
I think another card that's worth discussing for the deck is Seekers' Squire. I've seen it in some of the Esper Gift decks, and it seems like a reasonable inclusion. It places a body on the board early, smooths out your draw, and can help fill up the graveyard. With an ability that triggers when it enters the battlefield, it's also a decent option to bring back with Gift. Playing a creature on turn two was often a key factor in a lot of games I've won with the deck, and it's part of the reason I still support the inclusion of Gifted Aetherborn despite its lack of synergy.
2 Champion of Wits
4 Striped Riverwinder
4 Curator of Mysteries
4 Archfiend of Ifnir
4 Vile Manifestation
4 Gifted Aetherborn
4 Horror of the Broken Lands
4 Lurching Rotbeast
Spells
1 Censor
1 Collective Brutality
1 Strategic Planning
2 Grasp of Darkness
3 Gate to the Afterlife
2 God-Pharaoh's Gift
Lands
2 Fetid Pools
2 Choked Estuary
1 Ipnu Rivulet
11 Swamp
4 Island
3 Flaying Tendrils
3 Drake Haven
2 Negate
2 Transgress the Mind
3 Spontaneous Mutation
1 Strategic Planning
1 Ruthless Sniper
Round 1: Ramunap Red, 2-1
Round 2: Bant Planeswalkers, 2-1 (They ran both Cast Out and Angel of Sanctions, so the trick was not relying on the Gift plan)
Round 3: Mono-Black Eldrazi, 2-0 (This felt like a really good match-up. It helps when your two-drops can trade with Distended Mindbenders)
Round 4: Grixis God Control, 2-0
Round 5: Mono-Black Zombies, 2-1
Round 6: Ramunap Red, 2-1 (This was a finals rematch against the person I faced in Round 1)
This deck was really fun to play! Overall the only deck I really struggled against was Ramunap Red. A couple of the game wins I had against it were from my opponent drawing poorly, and I could have easily lost were luck not on my side. Flaying Tendrils helped a bit, especially since your two-drops survive it, but it definitely was not as good as I had hoped. Gifted Aetherborn was an absolute all star in nearly every match-up. In the future I think I'll actually try to complete the deck so I'm not running random one-of cards and to shore up the match-up against red.