Phyrexian Nightmare
The idea of the deck is to abuse the low cost and high power of Phyrexian Dreadnought by using cards that allows one to ignore/cheat its triggered ability. It is possible to play it as early as turn 2. This deck is meant to beat the opponent quickly, preferably by turn 4.
CREATURES:
Phyrexian Dreadnought is the main threat of the deck. The idea of a 12/12 for {1} is pretty good - especially considering how easy it is to cheat its triggered drawback ability. It's Death's Shadow on gear.
Eldrazi Mimic/Renegade Doppelganger can be sacrificed as Phyrexian Dreadnought enters the battlefield, since they'll copy its power before its triggered ability resolves. Renegade Doppelganger is usually better, since it benefits from Phyrexian Dreadnought trample. Multiple Eldrazi Mimics and Renegade Doppelgangers can finish the game by becoming an army of 12/12 monsters until end of turn.
Lazav, the Multifarious synergizes pretty well with Phyrexian Dreadnought, considering its low cost and the fact that Lazav, the Multifarious won't need to worry about the drawback of Phyrexian Dreadnought ETB ability, since it'll already be on the battlefield when its activated ability resolves.
Trinket Mage, can tutor Phyrexian Dreadnought.
NON-CREATURES:
Illusionary Mask is a tricky card to understand, and easily as ridiculously powerful as it is expensive. When on the battlefield, it is possible to play any creature card without having to worry about the color in its mana cost NOR the 'enter the battlefield' drawbacks. That means it'll be possible to summon as many Phyrexian Dreadnougth as desired as vanilla {1} 12/12 creatures! Plus, since it'll be face-down, it's still possible to pay more mana in order to trick the opponent, since he won't know which creature it is until you decide to turn it face-up (for free!).
Stifle/Trickbind counters all drawback triggers from Phyrexian Dreadnought. By using stifle, one can play Phyrexian Dreadnought on turn 2 for maximum disrespect. It's also pretty useful against other creatures with troublesome triggered or activated abilities.
Standstill is a great card considering how quick the deck is, and the fact that its early shenanigans are usually followed by a barrage of desperate cards trying to stop the stomp.
Sundial of the Infinite is another tricky card. While ending the turn might sound silly and pointless, the fact that it interrupts any effect or ability in the stack makes it pretty amazing card. One can end the turn to counter Phyrexian Dreadnought drawbacks. Also, if you're feeling like being silly, you can counter any counter your opponents might try to use (even though it'll also counter your spell, alas making it a pointless play only meant to disrespect your opponent).
Unearth can help one dig the deck for Phyrexian Dreadnought or bring it back from the depths of the grave.
Fabricate can tutor Phyrexian Dreadnought or Illusionary Mask.
Artificer's Intuition can tutor Phyrexian Dreadnought.
Brainstorm as always will filter the hand in search of Phyrexian Dreadnought or any other synergy card or land.
MAYBEBOARD:
Counterspell might seem like an easy choice for any blue deck, this deck rarely leaves any land untapped and its high 2 mana cost might slow things down. It doesn't really seem to fit the theme, and it'll bring it closer to those control normies, which I despise.
Eater of Days is a very dangerous card, since neither Eldrazi Mimic nor Renegade Doppelganger can deny its turn-skip drawback, plus its pretty high cost makes it much harder to pull off a synergy than Phyrexian Dreadnought - but the fact that it flies makes it a great finisher, especially if Renegade Doppelganger is already on the battlefield.
Cemetery Puca can become Phyrexian Dreadnought by paying {1} after sacrificing it (in case cheating its ability is not an option), or if it is destroyed somehow. It's not as useful as Eldrazi Mimic/Renegade Doppelganger, considering how expensive it is, but the fact that it becomes a permanent copy of the creature makes it pretty amazing for longer games. It also doesn't rely on creatures entering the battlefield to grow. Fabricate took its place. Good card for grindier games.
Cryptoplasm, much like Cemetery Puca seems like a great card, but waiting for the upkeep means it won't be able to attack at the same turn Phyrexian Dreadnought is summoned, which kinda sucks to be honest.
Torpor Orb is the card people usually use with Phyrexian Dreadnought, since it automatically denies its triggered ability, but that also means Eldrazi Mimic/Renegade Doppelganger will be useless. It's a great card, but too much of a burden most of the times.
Spellskite is good for protecting other creatures from removals. If you like sideboarding, go for it and jam a set of these bad boys in.
Stubborn Denial is a cheaper Counterspell, and it seems pretty good considering it's not hard to pull off its Ferocious ability. Jam it in the sideboard, if you're playing that kind of game.
Etched Monstrosity left so Trinket Mage could take its place. It's not a bad card, just too expensive for what it does and not very good by itself. Think of it as a {5} vanilla 10/10.
If you have any suggestions, I'll be eager to hear them. And thank you in advance!
Ps.: This is not a competitive deck, hence its nonexistent sideboard. If you want to try your luck against whatever meta poisons the competitive scene, be my guest.