Infidel Infiltration !

Hey, this deck is very reminiscent of West-Wind Herald combo, where you try to go off with West-Wind Herald, Mirror Image, and Bad News to OTK the opponent. I like the idea of a deck that's set up to abuse infiltrate cards, but I'm concerned that your main enabler (Iceberg Scattershot) is so expensive and so fragile. Maybe some cards like Vara's Intervention or Ghostform could be worth it? They aren't good cards, but getting in with a Desperado or Gorgon Fanatic is certainly worth a card and 1 power.

This deck also "screams" (excuse the pun) for Haunting Scream. Screaming back a Fanatic or Desperado is amazing value, and it also has great synergy with dark return. For this reason, I'd prefer playing Kerendon merchant and having a copy of haunting scream and dark return in the market. Scream is a far superior infiltrate enabler to iceberg scattershot, both in terms of cost and resilience to removal.

I'm not convinced about the Stoneshaker/Firemaw/Herald/Yeti Spy package, some would be interesting if you had the full infinite combo but as is I think those cards are just a bit too weak in general.

Your removal suite also needs a lot of work. You're currently running 2 Deathstrike and 2 Annihilate. Deathstrike is honestly just unplayable at this point, since it's so much more expensive than the other options and I think In Cold Blood is just better. Notably, you aren't running any copies of Torch or Permafrost, two of the best removal spells in the game. I also think annihilate should be a 4-of, or maybe 3-of with one in the market, because it's such an efficient answer to Sandstorm Titan, which is a huge problem for this deck otherwise. Playing all the cheap removal possible would help this deck a ton, since you can always kill 2 of your opponent's units to clear the way for desperado/gorgon fanatic. The key to removal is that it's ideally cheaper than your opponent's unit, so that you gain tempo when you use it. If your opponent spend 5 power for a world bearer behemoth and you spend 1 power to permafrost it + 4 power to play an iceberg scattershot, you're gaining a ton of tempo. On the other hand, if you have to spend 4 power to death strike it then you're staying tempo-neutral. Deathstrike has some use in control decks because versatility is more important than tempo for them - they need to be able to answer any and every unit the opponent plays. This isn't a control deck, so you're more interested in getting ahead with cheap removal .

I appreciate your point about card advantage and not needing more card draw, but cards like Quarry and Cull the Deck are more for helping you to draw into your powerful cards and assemble your combo. I think 4 Quarry is a good idea, because the card is just so strong for so little cost.

You're playing 3 unseal right now for disruption. I think Savage Denial and/or Sabotage are better options, because Unseal is much more expensive and odds are you're going to be wanting to answer a fast spell like torch anyways.

You're running 26 power + 2 seek powers at the moment. The key to building power bases is to identify how much of a certain kind of influence you need, and what turn you need it. The amount of card in a certain colour that you have also factors in, but the influence requirements on those cards is much more important. For example: If you have 4 double justice cards and 8 single time cards, I'd probably play more justice sources. It'd also depend on how cheap/expensive the justice cards/time cards are, the more expensive they are the less sources of that colour I'll need. Off the bat, your deck is fairly balanced in all 3 colers, but I'd recommend 1-2 more sources of shadow (Desperado and Deathstrike), and 1-2 sources less of primal (Only 1 double-primal card, and it costs 5). So I'd look to cut 1 primal sigil and both feln banners, then add 1 fire sigil, 1 shadow sigil, and 1 seek power (you're running 26 sigils and 2 seek power rn, 25 and 3 seeks is better since you don't have many 1/2 drops. As is, you need ~28 power sources since you have 2 5-drops and 8 4-drops. If you cut the death strikes, forepaws, and heralds, you could go down to 25/26 by cutting some seeks. Another point is the sigils themselves, I'd recommend running seats instead of banners and reducing the amount of crests in the deck, 12 crests in a fairly aggressive deck is way too many. If you cut some/all of the seek powers, you could consider a crest/banner/waystone power base. At that point, you'd want to cut all the basic sigils (and a few banners) for waystones.