Both 
The Deck
Code:
GU_1_2_CCmCCmCCQIAoIAoCFRCFVCFVKCaKCaCDDCDDIClIClKCiCEwKCbKCbICtICyKDfGBnGBnCAbCERCERICHICHKDLKDL
Things I'll probably change
Umber arrow needs to come out. I want to add another Beguiling Blade, too. I'm also considering changes about the makeup of the following cards:
- Makeshift Shiv
- Ronellan Sparrow
- Lokian Disciple
- Lady Marcella
I think in this deck I want to drop Marcella for another Ronellan Sparrow. Marcella is a touch out of place in this deck. She's great against nature unless they are running Faeflames and she isn't helpful against control magic. We also have Uncanny Rogues giving us some deadly options without the downsides.
Basic Idea
Go face. Go fast. Every creature in this deck (except Beguiling Blade) is guild, so Frumentari Instigator is key for refilling your hand. Without him, you can easily gas out and lose. Patient Pickpockets are in there for the same reason. They are arguably just as powerful (maybe stronger?) than Marsh Walkers.
This deck is particularly well-suited for nature and magic matchups.
Against Nature
Bound by Her Will is fantastic against their 1 drops. 3 mana seems like a lot to pay for a 1 mana but consider: they are also losing 1 mana worth of stats and nature stats per mana are the best. Plus, it makes their aoe buff cards much less effective.
Our strength steal gives us other options to deal with them. Nature is the only god where face isn't always the place. The current meta decks need board. If you can reduce their strength for favorable trades, take their creatures out. That way, they don't come back to bite you when buffed.
Uncanny Rouge is also fantastic against nature. We have echo tokens, Denholm skulkers, and plenty of other targets for deadly.
Finally, our hidden creatures aren't glass cannons like Shadow of Lethanon. They can't be pinged off. If we can draw out Canopy Barrage and Lightning Strike early, then our Guild Enforcers and Bruisers win the game for us.
Against Magic
I hope you like racing. At 6 mana the tide shifts drastically in their favor. Our hidden creatures + buff cards give us the ability to do a ton of face damage, though. There is an art to how much to buff a single card though, and I'm still trying to figure it out. Right now, I'm thinking to only use one buff per card (unless you have lethal). For example, boosting your Armor Lurker to 9 damage is nice, but Magic will clear him out next turn. Even if you have the mana to hide him, any of their board wipes clear him. The only exception to this is Switch Duelist. An amazing card for buffing. Do 9 damage and then flip to a 1/9? Nasty.
Differences from similar Deception Decks
Deception has several hidden options at 5 mana from various expansion sets:
What makes Bruiser stand out is its 4 hp. This is key to surviving Shaped Blast. It's also hidden until you attack, which gives you more flexibility to choose the right moment. Finally, 4 HP means that you can hide him after attacking. I might even do it against magic if he's the only card on board to bait out Shaped Blast. They have to choose: take 6 (or potentially 9 if I buff it) more damage or waste their best AOE?
Running 2x, and no, not just because I have them in gold! I can't imagine running a guild deception deck without them. They can be hidden each turn because of the armor or they can serve as a sturdy wall to buy you time. They count for Selfless Guildmate and Frumentari. It's very common to have a 6/5/1Armor GE hidden for a few turns that wins you the game. When hidden, the only thing I can think of that can take it out is a Lightning Strike + Canopy Barrage (if it hits). Even so, that costs your opponent 5 mana + 2 cards leaving you way ahead.
The "Deadly Package". Nothing ruins a Big Beast like a surprise 1/1 deadly skulker. Also, the wording on Denholm is important: "At the end of your opponent's turn". This means that on your turn, the new skulker can attack. It will spawn with the "ZZZ" but then quickly clear and 'wake up'. Denholme is not so great when facing Rapture Dance or control magic, but the skulkers get to attack before they can be killed, which means at a minimum, you can go face and generate 3 favor. They aren't guild, but can be buffed by Dark Knives.
These cards are taking the place of Ludian Thespian. Having 6x buff cards greatly increases the chances of a bricked hand. If you run Ludian, then I'd consider dropping either Selfless Guildmate or Dark Knives, but I strongly prefer a 1 mana buff card that bricks compared to a 4 mana card with no target and 1 hp.
Conclusion
I didn't have any games recorded, but I wanted to toss my $.02 into the Guild Deception conversation. Once I tweak this a bit more, I may post some gameplay. This is definitely a fast deck and is a nice change of pace.