This is a more competitive EDH deck. I'd say it's on the upper end of casual, but it's not quite cEDH. This deck is literally just Mono Blue Control until you assemble your game winning combo.
HOW DO YOU WIN?
Bruvac wants to combo off and mill each opponent with a kicked Maddening Cacophony while Bruvac the Grandiloquent is on the field. This game winning spell can be tutored up from Spellseeker, Mystical Tutor, or Muddle the Mixture. If Maddening Cacophony gets countered or ends up in your graveyard, Snapcaster Mage and Mystic Sanctuary can get it back to hand.
You'll have to protect your game winning spell, so there's 14 Counterspells in the deck. They include: Pact of Negation, Swan Song, Arcane Denial, Counterspell, Mana Drain, Memory Lapse, Muddle the Mixture, Negate, Remand, Unsubstantiate, Fierce Guardianship, Force of Negation, Rewind, and Force of Will. Narset's Reversal, and Twincast can also be used to stop your spell from being countered, by copying a your opponent's Counterspell, and contering it. (So there could be 16 Counterspells)
This deck can also just straight up one shot a single opponent with cards like Fleet Swallower, Terisian Mindbreaker, and Traumatize, but Bruvac needs to be on the field for these to work.
I considered running Corrupted Conscience as an alternate Win Con. Let me know if you think that's a good idea after checking out what else my build has.
KEEP YOUR MANA UNTAPPED FOR AS LONG AS POSSIBLE:
Mono Blue Control loves to have a fistful of cards and pass the turn. Two cards that really take this strategy to the next level are Vedalken Orrery and Leyline of Anticipation. If you have never began a game of EDH with a Leyline of Anticipation on the field I don't know what to tell you. It's dummy good. You haven't truly lived yet lol.
Spells that interact with your opponents things while leaving mana open are super powerful as they allow you to play multiple spells per turn cycle.
Snap, Frantic Search, Rewind are all essentially free to cast as long as they resolve. I wish there were more cards like this. I also considered running Unwind, and Treachery. Let me know in the comments if I am missing any.
Similarly, Pact of Negation, Fierce Guardianship, Force of Negation, and Force of Will are all free Counterspells. Cards like this allow you to tap out with a little more confidence.
CARD DRAW:
Draw Spells Include: Arcane Denial, Remand, Frantic Search, Windfall, and Consuming Tide.
Artifact/Enchantment Draw: Howling Mine, The One Ring, Mystic Remora, and Rhystic Study
Creatures That Draw Include: Faerie Mastermind, Kami of the Crescent Moon, and Consecrated Sphinx.
RAMP:
We are running Ornithopter of Paradise, Thieving Skydiver (This is EDH, your opponents will be playing mana rocks that you can steal), High Tide, Mana Drain, Mana Crypt, Sol Ring, Arcane Signet, Fellwar Stone, Sapphire Medallion, and Extraplanar Lens (All 28 basic lands in this deck are Snow-Covered Island so this will not help your opponents running "Islands")
Removal Spells Include: Pongify, Snap, Unsubstantiate, and Imprisoned in the Moon.
Board Wipes Include: Thing in the Ice
, Cyclonic Rift, Consuming Tide, Whelming Wave, Evacuation, and Flood of Tears.
Fog/Combat Tricks Include: Flatline, and AEtherize.
Staxy Pieces Include: Silent Arbiter, Meekstone, Ensnaring Bridge, Overburden, Back to Basics, Propaganda, Glacial Chasm and Maze of Ith