Built to destroy lands while running a very Kefnet friendly deck while also using the guild-gate package for ramp/card advantage, since very little needs to be happening earlier in the game and the deck really just looks to go off in a few really big turns.
Star of Extinction is pretty much the saviour of the deck for actually winning and Gate's Ablaze is essential for surviving aggro. Star of Extinction also provides the ability to deal with planeswalkers, which have wormed into nearly every deck since WAR was released. Taking out pretty much everything while putting your opponent down a land is a pretty good value, has always been, but is even more abused here. Kefnet can allow you to cast one on turn 4-5 while leaving one in hand, and later in the game casting one off of Finale of Promise is actually pretty reasonable, tripling a Star of Extinction means your opponent should be pretty low on resources. The most crushing play I have seen is using Star of Extinction to destroy a board while a Nissa was out, destroying many lands in the process.
As for the gameplan, it is to draw out the game as long as humanly possible. Kefnet is the only creature, not only empowering the deck more and allowing mental turns but it also offers a reasonable blocking body. The protection is nice, as you can draw into it within a turn or two, although keep in mind you have four in deck so ditching a Kefnet in the deck isn't the end of the world. The actual, true wincondition is Clear the Mind, interestingly enough. Ciruitous Route allows you to fetch out lands fairly fast, thinning your deck and creating a loop using Clear the Mind, allowing you to churn your deck indefinitely. I would like to only run 2, however jank must fear jank, and a stray Ashiok, counter, or other sabotage can easily cause you to lose, so I have 3 as a cushion (actually kept me alive against an Ashiok deck, after I locked the game down I looped the same 15 cards over and over).
Rubble Reading usually is strictly better than Demolish, however Demolish can attack non-land sources of mana. Being able to blow up a Chromatic Lantern is far more valuable than blowing up a Swamp. Perception is for refueling, with the upside of being able to trigger off Kefnet.
As with all land destruction decks, it struggles against opponents who flood, while it easily crushes decks that stutter or runs as efficiently as possible. Probably dies against mono red no matter what. Dies to any sort of stuttering. Really weak, really janky deck, but fun to pilot if it gets off the ground.
Sideboard:
Transformative in one hald of it, allowing the deck to switch into the typical Guild Gate package of Rams and Colossi. Narset's for control matchups, to slow them down since if they are drawing a ton of cards, it will undo your land destruction, plus it will allow you to find other cards faster. Bond of Flourishing is in the sideboard for it's lifegain to help against monored, however it might be good enough to be in the mainboard.
Current deck considerations:
The deck feels pretty slow, assembling mana to power up some really heavy plays. Being able to actually deal with counters might be nice, but I am unsure of how. Mono red really scares me with a deck like this, but I am unsure if anything I do to such a shell matters. Finale of Promise is really, really iffy to me. Super good some of the time, which doesn't usually mean good enough for a deck. Not only that, but Promise actually exiles spells, while Clear the Mind allows you to loop those spells for more value. Kefnet is also a really inconsistent card, so it may be better to adjust the shell by dropping Kefnet and adding a few copies of Patient Rebuilding or Psychic Corrosion for a mill kill, although if you have Guild Summit you don't really need to draw more cards in the case of Rebuilding. If you went with that plan, you would probably also drop the Clear the Minds and add something better. However, that wouldn't be as cool.
