Puschkin

This looks flexible on paper but if you look closer, all variants to "go off" need the same card, Heartless Summoning. 3 of them also all need the same card, Decaying Soil, while the other two need Myr Retriever ... twice! And then at least another card on top of it. In a deck without any tutors or library manipulation and virtually no defence. Have you playtested it? I really, really question this deck's consistency.

Sure, but this is a halfdeck. Diabolic Edict is more suited for mixing up with other halfdecks.

Oh and MINDSLAVER of course!!!
... and Puppet Master ...

Price of Progress
Unlikely Alliance
Curfew
Diminishing Returns
Limited Resources

And how do you cast him? With just 20 mana sources but 6 Pox effects I don't see him hitting play.

AmIcool is banned in EDH.

Well, Piper has summoning sickness and can't be actiavted the turn it comes into play. So, if you have 4-6 mana it doesn't matter if you have a Piper or Amulet, in both cases you will have to wait a turn. But if you manage to have 8 mana, you can use the Amulet right away. You might be able to protect the Piper, on the other hand a 1/1 creature is way more fragile than an artifact (everybody runs creature removal but not much artifact removal).

Besides, we don't mean to replace Piper with Amulet. Amulet should be in the deck as an alternative way to put your stuff into play. And if you have that, you don't need the Aspect anymore. Don't forget that Piper + Aspect are two cards you need, Amulet is only one.

STEEL OVERSEER!

Urzatron lands, really? Are you really hoping to ever complete those? It makes more sense to run Glimmerpost and Cloudpost because you just need 2. But I would play neither because you still missed some quality lands like Dust Bowl. Or MIREN THE MOANING WELL.

Arcbound Ravager isn't banned in Commander, right?

Junk Diver!

That's what I just wanted to write. Instead of trying to keep the Pipers alive with Aspect of Mongoose, I would add Quicksilver Amulets.

The Aspect is there to protect the Piper (I guess). Without him, no ElNazis.

Yes, Tamanoa and Manabarbs would cancel each other out just for you. This is an excellent idea! Collapsing Borders might also fight your theme.

That's too much I think. Lands you tap for the Perimeter can't be tapped for mana for Meditation. Also, I thought this was focussing on Ankh.

Yes, but I don't have Gates? And Sol Ring is restricted, that's why I run only one of them.

To be honest, most people I know don't pack Gaea's Blessing for the mill protection, they play it for the reshuffling. At least that was the case for the first 10 or so years. Meanwhile the game has become so fast and the graveyard a resource so important, that you don't want a slow reshuffling like Gaea's Blessing anymore ... back then, running a Blessing just in case you run into the occasional mill deck was not a big problem. If the opponent doesn't mill and you draw a Blessing, you just cast it and draw a replacement spell. But that doesn't cut the mustard anymore with all those crazy creatures and silly combos these days, the environment is too fast, even in Type II.

Well, it's still argueable, an Energy Field or CoP:Red for example can stop burn dead as well and then the burn player has to play around and maybe prepare for it during deck construction. If there are spells like Gaea's Blessing that have the potential to foil your plans and you know that, you have to prepare, too, like any other deck: Either exile their cards (Leyline of the Void for example) or have an alternative path to victory. I don't like milling at all, but the one mill deck I made (a multiplayer deck centered around Mesmeric Orb) was prepared for opposing Gaea's Blessing, I ran Jester's Caps in it. I think it is a bit unfair to blame cards like Gaea's Blessing. If you built a single-minded deck without backup plans, then you will lose against an opponent that runs the foil. If a Stompy deck loses because the opponent dropped a Moat and the Stompy player has no enchantment removal in the sideboard, you would call the Stompy player stupid, right? Same is true for mindless mill decks.
And try to see it from the other side - when milling was done with actual Millstones, you could defend yourself by destroying that artifact. But millers like Glimpse of the Unthinkable could only be countered if things like Gaea's Blessing wouldn't exist.

Also, as I pointed out, there are lots of cards out there that you don't want to mill. Which means you probably need something like the (Leyline of the) Void anyway. So, it's not that you have to put countermeasures in your sideboard because of a single card (Gaea's Blessing), you need these countermeasures anyway.

That's debateable. Recent mill cards are ridiculous and mindless in their own way. I would agree back then when Gaea's Blessing was printed because milling in those days literally meant using a Millstone or onw of the few other similar cards, a very slow and resource eating method. But now you have cards like Glimpse of the Unthinkable that require no planning ahead, no finesse, just straight mill to the face. It's like another kind of burn.

"Being a mill deck, in my experience, most players now are taken by surprise and their sideboards oftentimes don't have anything to answer mill."

In what environment? Mill decks are everywhere. WotC is trying hard to make mill viable for several years now, printing mill cards of ever increasing power. I run into a mill deck every second multiplayer game.

And while not every deck will have direct answers to mill like Gaea's Blessing, most decks utilize their graveyard in one way or another, so that milling them can be dangerous. Flashback, scavange, animator cards, dredge, the list of possible problems is endless.

Should a Walking Dread deck not have at least one Dread?

I advice against Pandemonium. Most opponents will get more out of it than you. And Final Fortune? in a deck like this?

Valakut Fireboar and Silent Arbiter might fit in well.

Greater Gargadon is a MUST in this deck! First, of course, it's deadly with your global sweepers like Jokulhaups. But additionally you can use it to get rid of any of your annoying enchantments and artifacts at any time (when they hurt more than they help).

Dust Bowl might be worth adding.

Squee?

And maybe Mishra's Factory?