Make servos, enchant, equip, chaos!
While I find many making spellslinger decks with Saheeli, Sumblime Artificer, this is a different direction: Enchantress!
The main point is to cast equipment and enchantments to create servos. Then, enchant the servos to create more servos, which can be enchanted, and the cycle continues. There needs to be plenty of equipment and non-aura enchantments to male sure you can start the cycle (can't cast an aura without a target, don't want to target an opponent).
I chose auras and equipment that enable flying and first strike to enable good attacking and blocking capability, whichever you need. A few auras allow card draw. Equipment is low equip cost, so it can shifted to a new servo easily, which allows you to hurl hulking masses at your opponent each turn without worry. Thirsting Axe is a prime example.
Synergy also comes into play in other directions, like with Ghirapur AEther Grid, Mechanized Production, Soulblade Djinn, Ravenous Intruder, Valduk, Keeper of the Flame in intuitive ways. Note that equipping Valduk's elemental after attack with Thirsting Axe will negate the downside.
Shrewd Negotiation and Eyes Eveywhere are useful no doubt, but the real fun begins when you get to Daring Thief or Stolen Strategy. Daring Thief will have plenty of ways to tap either as a flying intimidating attacker, or because his aura allows him to tap without attacking. Thassa's Ire can help, too. Daring Thief will be able get almost anything (except planeswalkers require giving up Saheeli), especially enchantments (trading an aura away in most cases will be like getting something for nothing). Stolen Strategy is good for anything that isn't a land. Take an opponent's creature and turn it into a first striking flyer. Not just stealing, but also card advantage.
Corner cases include enchanting Irontread Crusher with Siege Modification, using Daring Thief and Eyes Everywhere to go after Planeswalkers, Sacing Emergence Zone with Soulblade Djinn on the field to cast a bunch of buffs after blockers are declared. Note that the existence of Emergence Zone will make opponent hesitate to block at any time.
And that brings us to Metallic Rebuke. Ideally, you can cast it any time, multiple times, even to counter a single spell if you have something to hold priority. It is admittedly more defense than offense.
I believe the biggest weakness is the start. It does not have very many creatures, and since Saheeli costs 3, you may have no creatures to block with until turn 4. This will be a problem against some decks, because this heavily revolves around Saheeli. I am considering swapping some flying auras with cheap flying and unblockable creatures creatures, like Triton Shorestalker, Wingcrafter, Siren Stormtamer, Cloudfin Raptor, and Mistcloaked Herald. Burning Prophet and Flux Channeler could also have a home here. Finding the right creature/aura balance may take testing and tuning. Other weaknesses are lack of hexproof and/or indestructible equipment and creatures. Of course, if Stolen Strategy pops out a hexproof creature, it will be stolen.
Final notes: This was made from cards I own. I realize there are better versions of cards out there, Lightning Greaves and/or Swiftfoot Boots would be great, but I am submitting it first as a proof of concept.
