First thing we should cover is that this deck is not going to win a lot. 

However the stars may align and one day it may actually win a game for you, it did for me. 

I found that the most effective way to use this deck is to throw Etrata, the Silencer into the grave then use Lazav, the Multifarious and Spark Double plus another Etrata or Spark to get 3 on board in one turn. Then just hope that your opponent doesn't have removal and 3 creatures you can exile and you win.

Other than that the deck isn't that hard to figure out, the surveil mechanic drives the deck to go faster while Thought Erasure and Sinister Sabotage gives you some control over the game.

Cavalier of Gales is a really good card and its ability, combined with surveil, is a really powerful way to fix your hand. Dimir Spybug and Thoughtbound Phantasm can tick up really fast and become big mid-game threats. Spark Double is a versatile card in this deck as it contributes to all 3 win conditions. Those win conditions being Etrata, Jace, or beat down by creatures.

Jace, Wielder of Mysteries doesn't work amazingly with surveil but it can help in the grind heavy match ups, and it helps toss things in the grave. Mission Briefing can actually have a decent impact on the game giving you a second use out of a spell, or first use if it was tossed earlier in the game. It also works in tandem with Soul Salvage to give you the confidence to toss everything into the grave.

Tyrant's Scorn helps to bridge the gap into the mid and late game but also allows you to recast a Spark Double or Lazav if you need it for Etrata. 

Etrata, the Silencer is actually not a terrible card, I mean it is bad but not terrible, it works as pseudo removal, if the opponent has creatures, and while it does that it puts a really slow clock on the table. That clock is also attached to a bomb across the world but it still does mean that the opponent is forced to work around the win condition. Sometimes while your opponent deals with the jank you end up winning because they forgot to deal with the 10/10 bug on the table. 

Put whatever you want into the side board as I doubt that anyone is taking this jank into a best of 3, but still I did throw some solid cards into the side board that can be exchanged in and out. 

Overall this is not a deck that I recomend anyone build to win. So unless you just happen to have the cards laying around or are a jank loving fool like myself then only build this at your own risk! Good luck gamers!