Here's my current tinkering with Hardened Scales for modern.
I'm running 4 [Song of Freyalise] and 4 [Tezzeret's Gambit] and a full set of [Throne of Geth] at the cost of no [Ancient Stirrings] nor [Welding Jar] with reduced [Steel Overseer] to 2 and [Arcbound Worker] to 3.
I think that the novelty of the deck with quite different play lines (compared with current regular Hardened Scales) helps your opponent to make lethal mistakes against unfamiliar cards.
The deck is somewhat more resistant to [Stony Silence], as it has fewer targets actually affected, far more ways to win than just [Arcbound Ravager] into Ballista or Inkmoth, and has a resilient big proliferate bash option - plus the mana from [Song of Freyalise] facilitates the defensive casting of sideboarded anti-enchantment instants.
With a [Hardened Scales] on field three proliferates is very likely game over, two is usually sufficient, and this can be done neatly instantly if they tap out, and doesn't even put you all-in. You can proliferate with 4 [Throne of Geth], 4 [Tezzeret's Gambit], and somewhat with the 2 [Steel Overseer] and 4 [Song of Freyalise]. Not only are 8 of these immune to [Stony Silence], but Throne and Song are fairly resistant to instant disruption once on board and can trigger without mana use on the needed turn. Throne triggering Song at instant speed is pretty back breaking as a 0 cost and hard to disrupt combat trick that gives everything +4/+4 (as tokens), vigilance, indestructible, and trample at instant speed! ... let alone if you sacrifice a Hangarback to Geth to trigger Song.
This deck designwise differs from regular Hardened Scales as I have ceased the attempt to make [Steel Overseer] stick through removal with [Welding Jar] - instead the deck aims to get an superior instant speed proliferate off [Tezzeret's Gambit] and [Throne of Geth] - these also draw cards, tick up [Song of Freyalise], and give us better offensive mid game top decks than 4 [Welding Jar] and 4 [Steel Overseer] and 4 [Arcbound Worker] - now we have only 2 Overseer and 3 Worker for 5 rather than 12 bad draws.
I feel that [Tezzeret's Gambit] is superior to [Ancient Stirrings]. Stirrings cost 1 green mana without improving your board state to tutor a colourless card from the top 5, whereas Gambit costs more - usually 3 colourless and two life - but both proliferates (hugely improving board) and draws 2, and won't whiff. Tezzeret's helps draw non Artifact cards - highly relevant for getting that sideboarded enchantment hate, card advantage, Scales, or a copy of Song. Gambit is also a huge combat trick, lethal if it triggers Song.
In response to targeted removal, wipes, or declaration of combat assignment the deck has the potential instant tricks: 1. proliferate 2.sacrifice the target to a [Throne of Geth] or [Arcbound Ravager], 3.sacrifice another modular Artifact to also pump a target with modular, 4.Fire off a [Walking Ballista], 5.uptick Song to get indestructible (via proliferate or [animation module]) or 6. pump with Pendelhaven .. There's a hundred lines of play which seems very good against tired players unfamiliar with the deck.
Regularly you can get all three triggers on [Song of Freyalise] in the turn (4-5) that you cast it, ie directly tick it up at instant speed [Animation Module]/[Tezzeret's Gambit] /[Throne of Geth] - this can all be saved for the opponent's turn or used as swinging. Note that ticking Song to 3 at instant speed stops most removal/wipes.
I'm unsure on [Inventor's Fair]
It just gives a life a turn at minimal opportunity cost. The tutor is really only useful if empty handed late game with spare mana, but it is at instant speed and is another complication for people trying to read what you might do with mana up. Post sideboard it could tutor effectively for mid game hate artifacts eg [Torpor Orb], [Dampening Sphere], [Grafdigger's Cage], [Pithing Needle] . It's nice but could easily be replaced.
This deck loves to leave mana up in the form of untapped creatures with a Song in play. It can play a really decent control vs aggro decks in this regard.
Animation module backed by Song and proliferate can be evil in your opponent's end step. You can create 3-4 servos and untap with all that mana (and then chain several proliferates, trigger Song, swing for 50...)
I'm thinking about [Chalice of the Void] as a step to moving the deck towards a slower more consistent control option that helps give great game 1 play against storm and arclight Phoenix decks. You have to be careful with not locking out your own plays, but this could be cast for 0 as another T1 Mox enabler (or with 1 counter) and then proliferated up to lock out the opponent as needed. The deck has no 3 cmc spells and this is a fairly good spot to sit, but it's also good to be able to lock a developed board against removal or those 2 cmc white enchantments. You can always later sacrifice a Chalice to Throne or a Ravager if you need to, but it also seems desirable to simply lock out cantrips and removal and then win with a flood of tokens, Inkmoths, and proliferate.
Would love your feedback.
