Draw
First and foremost the goal we will achieve is for a guaranteed extra draw and to make as much from that as we can. Vega, the Watcher + Yennett, Cryptic Sovereign
means we will either draw from Yennett directly, or cast a spell and trigger Vega to draw us a card. We can also draw with cards like Acquisition Octopus, Mask of Riddles, Rogue's Gloves; or some good old fashioned draw spells like Behold the Multiverse, Brainstorm, Opt, or Tales of the Ancestors. Other cards are also present to help trigger Vega with Dead Man's Chest, Ethereal Valkyrie, Fblthp, the Lost, and Monk Class; Future Sight + Magus of the Future
will both let us know what's coming (and cast it if we need to clear the deck to make sure both Vega and Yennett trigger). Sage from Beyond, besides being able to be cast for its Foretell cost, can make our nonhand casts even cheaper!
Who Benefits?
So we can draw a bunch of cards? Whats the big deal? well friends like Behold the Unspeakable
or more specifically the backside can power up our commander for massive damage, as will the Hand of Vecna and temporarily gaining a boost with the Diviner's Wand. Meanwhile Jace's Projection + Oneirophage
are both getting themselves bigger with each card drawn and Nadir Kraken is building an army of tentacles so long as we can pop in 1 extra mana each time.
Serve and Protect
So we can draw cards and get some big threats. We need to be able to protect our threats. So we use a number of backgrounds to offer different bonuses to Yennett: Agent of the Shadow Thieves can grant him indestructible, deathtouch, and a +1/+1 counter. Sword Coast Sailor allows him to be unblockable guaranteeing he won't be killed in combat. Feywild Visitor will allow us to keep growing tokens for a potential go wide strategy. Falthis, Shadowcat Familiar will grant the deathtouch, while Keleth, Sunmane Familiar can add another +1/+1 counter, and Esior, Wardwing Familiar will make our commander a little harder to target! Loyal Unicorn will grant us some protection across the board as well preventing combat damage to be dealt to our creatures and an added bonus of Vigilance, Loyal Subordinate will allow us to deal some damage to all our opponents before combat has even begun! Ironsoul Enforcer will let us regain some artifacts in the graveyard, while the Geode Golem will let us recast our commander for free should anything happen to him. Horn of Valhalla is a nice little trick if we cast it for X soldier tokens, and then as an artifact we can give another healthy boost to one of our creatures! Aqueous Form and Stealth Mission can be used for our Commander, however given all the support he gets passively, I would save these for Jace's Projection or Oneirophage. We will continue with some fun little tricks that ideally we get off the top of our Library through Yennett with Infiltrate to make one of our creatures unblockable, Kaya's Onslaught for a small power boost and double strike, and Warhorn Blast to give a decent power boost should we need it. Cards like Depart the Realm, Silverflame Squire, and Shepard of the Flock will all be drawn by Yennett and will give us the versatility of when we want to use them either to protect our own creatures or to remove an enemy creature. Leadership Vacuum will let us either remove an enemy commander or protect our own if we make a bad swing (sometimes a bad swing may be necessary to get the cards we need.) Szat's Will will allow us to remove some troublesome creatures but more importantly some graveyards and then make a good number of thrulls to use as chumps or to help power the Horn of Valhalla. Rounding out our protection is a couple of counterspells with Anticognition to let us scry 2 as well, and Controvert which could potentially be recovered and used again.
