Hello friends!It is that time again to visit the bank of jank and withdraw a shiny decklist! The list I have for you today is rotation proof and uses Tezzeret, Master of the Bridge to discount your planeswalkers and creatures, using my favorite planeswalker Saheeli, Sublime Artificer to create a ton of 1/1 artifact creatures. Once the board is full of artifacts slam the metal man down Karn, the Great Creator and grab no one's favorite creature Sphinx of the Guildpact then cast Masterful Replication and send your newly minted army of Sphinxes,(Sphinxii?) into your opponents face! 
Ok Lets get into the juicy details...
To start lets talk about the last revision to the list, Guild Globe is actually a really interesting card with some cool interactions in the deck. Originally I had put Guild Globe in to speed the deck up and be a cheap artifact and it does that really well. I figured the mana ability would come in handy eventually but after playing the first game with it in I found a pretty powerful interaction that it has with Renowned Weaponsmith. Yep, Guild Globe unlocks the weaponsmith mana to be used for any other card meaning you can get a turn 4 6 drop. These two cards in tandem give the deck more consistency which is vital in combo style decks.
On top of the synergy with Guild Globe, Renowned Weaponsmith also fetches Vial of Dragonfire which can get you a Saheeli, Sublime Artificer proc, or function as creature removal. Renowned Weaponsmith also helps to pay for some of the non-creature artifacts in the sideboard which is pretty cool.
I still don't know how I feel about Mystic Forge. Sometimes it helps, and in theory it should filter through your deck. The forge hasn't really helped me win a game but it has helped to win harder. So one in the mainboard feels good right now but the idea of cutting it and just using Karn, the Great Creator to fetch it also seems fine, play around with it see what works for you.
There are a good number of planeswalkers in this deck, and the reason for that is that Karn, the Great Creator allows us to fetch all of our important creatures when we are ready to play them. 
Karn, the Great Creator essentially gives us 15 more slots in our deck to play with at no extra cost.  Karn, the Great Creator 's flexibility is really powerful, the metal man is one card that plays like 10 distinct cards. On top of his fetch ability Karn, the Great Creator is also colorless which means you can cast him for free with Tezzeret, Master of the Bridge and off the top deck with Mystic Forge. The key to playing this deck lies in choosing the right cards out of your sideboard with Karn's ability.

I've said it before and I'll say it again Mu Yanling, Sky Dancer is an early game time bomb. If the opponent does not deal with her then you now have an endless value generator. Mu Yanling, Sky Dancer can also help to protect your key early game cards like Saheeli, Sublime Artificer.
That brings us to the obvious MVP of the deck, Saheeli, Sublime Artificer. When you are running only 8 creatures Saheeli, Sublime Artificer puts in work, and when each of the 1/1 tokens she creates discounts your cards, it becomes clear why the legendary artificer is vital to this deck. Even in games where you cannot find Tezzeret, Master of the Bridge Saheeli can still carry the deck, combined with Steel Overseer those 1/1's become big very quickly! You can also use a token to copy another artifact to use its ability, good targets include, Steel Overseer, Vial of Dragonfire, or Mana Geode. 
The other vital card to this deck is Tezzeret, Master of the Bridge, who unlocks the ability to play all the expensive artifacts and creatures for more manageable costs, and eventually for free! Tezzeret, Master of the Bridge's other two abilities are also very powerful. His +2 can just win the game by itself sometimes. The -3 doesn't happen that often but it can still grab some really good cards from the grave if the opportunity arises.
The other three planeswalkers in the deck are pretty straight forward in their use, Ugin, the Ineffable can be a 0 cost so that is awesome and worth playing for that reason alone. Liliana, Dreadhorde General is a bomb and deserves a spot in most black decks, also when you play her for 2 mana it feels really good. Narset, Parter of Veils does her thang, stopping draws and filtering your deck. 
Ideally you curve straight into Renowned Weaponsmith, Saheeli, Sublime Artificer, Karn, the Great Creator, and  Tezzeret, Master of the Bridge. With those on board you play a Sphinx of the Guildpact and turn all of your artifacts into copies of the sphinx with Masterful Replication and hit for 35 max damage on turn 6 with 5/5 fliers. 
Overall I found that Masterful Artifacts was a really fun deck to play, it is definitely unique and has some cool little interactions, it is rotation proof, and it is surprisingly a decent deck. By no means will this be a meta shattering deck but I do think it is worth playing if you want something different!

As always Gamers good luck and I hope you have fun!