Snacking: you'll ruin your appetite and put on a few pounds with small treats here and there
Mono blue control deck that tries for some interesting synergy spread through multiple interactions. Basically trying to force the game into a long grind and using the synergy of multiple engines to turn that tempo into material and that material into a win.
The idea for the deck came with trying to play Kozilek's Command in a mono color deck to take advantage of how sick a card it is and the fact that you can get away with playing it because of some of the colorless land options. In this case, one Ancient Tomb means the Command goes off nice and pretty, and since blue control plays otherwise cheap cards, you can get away with running Ancient Tombs and not bleeding to death.
Command also helps you dig through your deck, which makes the regular blue cantrips/draw mechanics get kicked into overdrive, as it lets you run fewer threats/combo pieces and still have access to them. Ancient Tomb + 2 islands and a Command sees 2 cards you can scry past plus all it's other fun nonsense, that you can use to either store mana for your combo turn/blocking/whatever, remove a threat, or clear some grave. In total, that brings the cantrip count in the deck to 10 with an extra 2 Stock Ups and 3 Tamiyo chances for clue tokens, plus fetching the Undercity Sewers for the scry, so you're going to move through the deck at a quick, cheap, and profitable pace to find what you need, be they answers or action.
The next step was trying to utilize Ancient Tomb for more than just the Command (which is just a nice synergy, not the point of the build), which brought me to the realization that being able to pump for 3 mana on turn 2 meant you could cast Hullbreacher during opponent's endphase then mainphase your own Day's Undoing on turn 3, and that's the ballgame. You've got a full hand, mana to spare, a clock on the board, and opponent has whatever he's managed to field turns 1-2(and/or3). That's a hell of a quick synergy beat made possible by just a little extra mana that costs you a pittance in life (in relevance) and fits in with the Command synergy as well as some other fun twists, such as:
-accelerated Saga gaming (great win condition mixed with great stall tactic)
-hardcasting Force of Will on 4 lands when the game's ground to a halt
-popping a Stock Up for 2 lands
-cracking clues for 1 land (massively helps with Tamiyo)
-playing and activating your artifacts with 1 land
-utilizing Campfire to mitigate life loss and still produce mana
-hardcasting Lorien Revealed on 4 lands (hopefully allowing mana up for counters)
-cheating in Brazen Borrower for 4 lands in a turn
-hardcasting Devastating Tide on 4 lands if you can't miracle it
-pushing Jace in on 3 lands (mana up to counter)
The rest of the build builds off this idea indirectly. Saga is a win condition and a stalling tactic, and fetches answers, blue mana if you need it (Seat of the Synod), and/or your Campfire grind engine that makes absolutely perfect use of unused mana to keep you alive and ticking against decks with a damage clock and helps against decking by a Tamiyo mega draw and/or all the cantrips. Brazen Borrower stores itself so you can pull off your Day's Undoing and not lose it, plus you can bounce something and make opponent lose it (if you've got the mana/tempo), making it a delightful spot removal/damage clock combo. Same with Spellbomb.
Win conditions are also baked into the build in a lovely way, and apart from the single copy of Murktide (which admittedly has some anti-synergy with Day's Undoing), all work as engine pieces as well as wincons, maxing out the synergy like crazy:
-Tamiyo has the draw shenanigans and makes clue tokens that help with Saga tokens
-Hullbreacher is a decent beatstick, especially against an empty field and hand via the combo
-Borrower is a decent beatstick with flying
-Jace fixes problems and builds to a wincon (plus works with miracle for Devastating Tide if push comes to shove), and can bounce a threat that gets eaten by Day's Undoing or just kill tokens
-Saga tokens are going to be 3/3's (hopefully), but get big and bad with Tamiyo clues and Hullbreacher treasures
Thoughts appreciated.
(Note: I'm unsure of running the Dismember because of the potential life loss when stacked with the Ancient Tombs, but I'm currently for it because of the Undercity Sewers and Campfire plus the old 'the critter's gunna hit me for more than 4 anyway' argument)