Turbo Fog
There is a lot of cards in the format that really hate on creature decks and that can be a pain to play against if your only wincon is creatures. But nothing is probably as annoying to play against as a deck that fog EVERY SINGLE TURN. And that is of course exactly what this decks wants to do.
The instants we use for preventing the opponent to do combat damage are Fog (of course), Holy Day, Darkness and Festival. All but one of these cards prevents all combat damage for the turn and the last one prevents the opponent from even attacking. The problem is that you need one of these cards in your hand every single turn to be able to survive. That is where the name turbo comes in.
Turbo is a word you can see in many deck names, like Turbo Stasis, and it usually means that the deck is powered by Howling Mines. That is the case in this deck as well and with the help of Howling Mine and maybe also Sylvan Library you should be able to always have a Fog in hand.
The things that can really screw with this plan are counterspells and Mind Twist, so it’s not a bad idea to play counterspells of your own. You can also choose to play some protective permanents like Moat, Island Sanctuary or Arboria. They all have their downsides and aren’t giving you perfect protection, but they can hold the fort until you draw more fogs. The Sanctuary is usually a really bad card but with Howling Mine it is actually playable.
If you choose to play Arboria one win condition you can use is Millstone, as activating it doesn’t turn off the Arboria. Also, Millstone combos quite well with Sylvan Library so you can keep finding your Fogs. Overall, Millstone is a nice wincon in this deck. Another wincon is of course Mirror Universe and Fireball as Mirror synergizes quite well with Sylvan Library and protects you against creatures.
Last but not least, don’t leave home without adding a Circle of Protection: Red or maybe two, as Fog does little to help against burn.
And as a final note, the big problem with this deck is that Fog doesn’t do much at all against control decks with few creatures. But how to solve that we will leave up to you.