You want to build a deck that can harness Ashiok as an engine, and anything else is supplemental.
If you're playing against Dredge, and you have Ashiok main and can land it game 1, it's probably too slow, but it could very well turn the game around. (Note: You can play Ashiok off only a Black Lotus, unlike Dack.)
If you're not playing against Dredge, I think you want to be piloting a deck where -1 Ashiok, targeting yourself has the effect of either drawing cards (Yawmogth's Will, Snapcaster, Ramunap, Life from the Loam, etc) or powering Delve (Treasure Cruise, Dig Through Time, Tasigur). You are gaining resources (and knowledge about the remainder of your deck), and hindering your opponent.
For comparison, Bazaar moves 5 cards (2 from library to hand, and 3 from hand to graveyard). This one moves 4. It's not a land, and you likely won't play it on turn 1, so it's clearly not as powerful on the two axes, but it does give us some insight into it's raw max potential. I figure it's somewhere more than 80% of Bazaar. It has two upsides, pitches to FoW, soaks up damage, and doesn't take up a land slot.
I still debate with my friends how much Treasure Cruise or Dig Through Time should cost to be "fair," but they both just got cheaper by four mana. And we already know Yawgmoth's Will and Snapcaster are both busted.
Ghost Quarter just became Strip Mine, and Ghost Quarter has seen play in Vintage. UG could make this a thing. UB & BUG? Probably not. I don't think this is a real point, but I wouldn't be surprised if someone tried a thing.
@theactualsaturn Ghost Quarter and Field of Ruin don't work, because they aren't an effect the opponent controls.
I love this card and think it's not as slow as people think. Turn 1 land, mox - turn 2 land, Ashiok. It's not like Vintage is a format without a crapload of moxen, and this can work off jet OR sapphire OR two lands that produce blue and/or black + ANY moxen. The turn 1 on lotus is going to be rare...but if you drop this thing turn 2, the opponent is still stuck with multiple fetches and dead tutors.
I'm pointing out Kaya mostly because "Its not Dack" is just about the silliest argument against this. Its like all the people that yell "Its not JtMS" for every 4 mana walker. You are better than that.
This feeds your DRS/Tarmogoyf, mana denies any Fetch lands your opponents play later in the game, shuts down game ending spells like Tinker/Dark Petition, stronger hate against Dredge as it nukes their entire yard (when combined with DRS or Wasteland should be game ending). Kaya is the latter, but that's it. If you don't want to play it that's fine, but it serves similar value across a number of matchups as these other 3 mana walkers. I can understand Kaya #1 being better in that list, but drawing this instead of a 2nd Kaya would be a benefit towards fueling Kaya's ultimate.
This is also playable in Landstill (or any other wasteland based control) the 1-sided Mindlock Orb effect against storm and -1 is very strong against Dredge. Both abilities play well with any strip effects, e.g. Wasteland/Ghost Quarter/ect. Her -1 is also synergistic with Crucible. It is highly matchup dependent though so I don't think this is a make or break card for these decks.
@vaughnbros I'm not making the "Dack/Planeswalker Gambit" TM. I'm making the argument that self-mill is overrated. Weren't you testing with us when we were trying to make Thought Scour work while Dig + Cruise were still legal? The problem was that you had trouble finding or resolving the cards that converted the self-mill into an advantage and that's why Preordain and Probe ultimately proved better.
Landstill can't beat Dredge, certainly not with this card. It had a sub-20% match win rate already, lacks Moxen to accelerate out expensive hate, and generally struggles to deal with even a couple creatures from Dredge. The last thing it needs is a 3 drop hate-piece that dies to a single Hollow One attack.
You can try it as a Prison card but it's pretty expensive at 3 mana. Or run it in a UB Turbo/Depths Lands shell where the self mill can find Life from the Loam and Bazaar and cast it off Urborg. Just remember (as others pointed out) that it doesn't work with Ghost Quarter.
@vaughnbros you can cast this turn 2 as easily as they're can cast Survival turn 1 and have 1 turn unimpeded, making this too slow. That's my point. Is this good enough to see play when it "kinda hurts" whatever you're trying to hurt?
I feel as if you are downplaying just what "kinda hurts" means.
It piths all of their fetches as well as survival, and depending on the build many even demonic tutor, etc. It removes any progress they may have made already by killing any vengevines in the yard. It will almost undoubtedly be used with other gravehate because that is how grave hate works.
I think this is more than kinda hurts frankly. No it is not a 1 card silver bullet, but it is certainly strong enough against a large swatch of decklists that it may be viable, and synergistic with enough stuff that its not like you are just shoving it in for one reason only.
This could have had some potential as a storm sb card that is more versatile than just for the dredge matchup, it would be pretty easy to cast on turn one with rituals.
The main issue I see is that this is actually really bad as dredge hate, all they have to do is sandbag the bazaar activation to your EOT and go nuts on their turn.
My favourite deck to play is "survival". I would not be so scarred of this one - it is NOT instant speed. In your end phase I would put up the graveyard with survival and/or BoB, then in my main I would do, what my deck does - trigger and attack. My plan B would be as often to go aggro, as I do quite often, to all those that oversideboard against me.
The key limitation on these cards is again their ability to be removed via combat (unlike traditional hate pieces). So yes, this card does have a significant impact against Survival if it stays in play. The challenge is going to be keeping it on the table, especially since it cannot gain loyalty and it's -2 puts it in range of a single Basking Rootwalla or Hollow One.
A planeswalker can be attacked, but also can't be disenchanted. This will make this effect stronger in some matchups, like against Storm, and weaker in others, like against Survival.
The uncommon walkers not being able to grow certainly makes evaluation different from a normal planeswalker. However, unlike creatures/enchantments, they all still have a very wide array of effects. E.g. This card has 3 distinct powerful effects.
There are a large number of planeswalkers that are great against creatures and dealing with things sorcery speed, one of the issues with playing a lot of walkers was dealing with these problems with supplements like a large suite of counterspells, these cards kind of address that issue to some degree. You still have the problem of the curve mostly starting on 3, but there are certainly options to deal with that.