Reasons for each card:
Solitude: No explanation needed.
Shefet Monitor: Cycler that can access the 1 copy of Scavenger Grounds for graveyard hate.
Titania, Protector of Argoth: One of the primary win conditions of the deck in combination with Zuran Orb. Has slight synergies with Flagstones of Trokair to help deck thin.
Yasharn, Implacable Earth: Helps make land drops and can shut down fetchlands among other things. A 4/4 body isn't terrible either not to mention that it can be gotten by Glittering Wish.
Conduit of Worlds: This is a bit of a test slot, but it's main idea is a way to recur destroyed engine pieces and make additional land drops by using the cycling lands. Note the sorcery speed restriction on it!
Cast Out: Can cycle and remove obstacles if needed.
Eternal Witness: Mainly used for the ETB effect, but being a creature has marginal benefits.
Astral Drift: The card the deck is based on. Designed to help keep creatures at bay and abuse ETB's.
Kitchen Finks: Lifegain to help stabilize in the early game. Persist counter can be reset for extra durability.
Renewed Faith: Early game cycler that can help you stay alive during early turns.
Skyclave Apparition: General all-around exile for low costing permanents. The drawback of giving an opponent a creature can be negated by sliding (using astral drift) the creature out. Helps buy time at the least.
Edge of Autumn: Early game ramp that synergizes with Flagstones of Trokair as a cycler to act like a psuedo-fetchland. Better used as ramp early, but being a free cycler in a pinch has uses against opponents thinking they can sneak in a kill spell of your creatures. Note the 4 lands or less as a ramping restriction.
Glittering Wish: Used to retrieve hate cards from the sideboard. One of the first cuts in sideboard games, especially if you are bringing in the retrievable pieces to play them faster.
Prismatic Ending: Generic removal spell for problematic permanents.
Zuran Orb: Works with Titania, Protector of Argoth as a combo finisher or gains life in a pinch. Use this to sacrifice Flagstones of Trokair to fetch Scattered Groves or sacrifice enough lands to make Edge of Autumn able to find lands again. (It's bad deck thinning, but probability might require it sometime.)
Scavenger Grounds: The only source of graveyard hate in the main. Can be fetched by Shefet Monitor.
Flagstones of Trokair: Probably the best land in the deck. Can be sacrificed to find Scattered Groves giving you a green source for later turns. Additionally extra copies can be used to deck thin or create tokens with Titania, Protector of Argoth. Also a small safeguard against ponza like strategies.
Tranquil Thicket/Secluded Steppe/Scattered Groves: Lands that cycle to keep Astral Drift doing things.
Mistveil Plains: Fetchable by Flagstones of Trokair if needed. Gives a small amount of long term utility although it can be hard to activate at times. Generally worth waiting until later game to find.
Hall of Heliod's Generosity: Just here to recur Astral Drift if needed.
Plains and Forest: Should be self explanatory.
Sideboard Choices: Most choices in the sideboard fall into 1 or more of 3 categories, wishable, hate-bear, or other.
Knight of Autumn: Flexible creature that provides artifact/enchantment hate for higher costing permanents. The lifegain can be relevant against aggro/burn strategies as well.
Yasharn, Implacable Earth: Same reasons as above, but wishable.
Sigarda, Host of Herons: Wishable beater if needed.
Kitchen Finks: Wishable form of lifegain if needed. Persist counter can be reset with Astral Drift to be a road block against decks like burn.
Gaddock Teeg: Wishable hate bear for various combo decks. Off recollection the following cannot be cast with this in play: Goblin Charbelcher//The One Ring/Gifts Ungiven and so much more.
Selesnya Charm: Wishable utility card for the most random of occasions. Almost never brought in from the side.
Sanctifier en-Vec: Hates on reanimator, burn, scam and other stuff I'm not thinking about at the moment.
Auriok Champion: Similar to above.
Wrath of God: For decks that put several creatures into play in the early game or for decks that use creatures that would be very painful to use Astral Drift on. Don't be afraid to wrath your own board since you have ways to recur things.
Collector Ouphe: For artifact decks like Amulet Titan, Door to Nothingness, Grinding Station and so forth.
Thragtusk: Value creature to use with Astral Drift against decks that run a reasonable amount of removal. Can be sided in with wrath due to leaving an additional body afterward.
If you took the time to read all that, my apologies. We'll go the more interesting stuff now, like what to look for in an opening hand.
Opening hand:
Generally speaking, going into a match blind I like to look for 2/3 lands and hopefully an edge of autumn. This will allow you to play and cycle with astral drift on turn 3 most easily. If not that, then something that impacts the board in some way. I'm not terribly picky usually.
Sideboarding:
Vs control I like to change into an aggro deck cutting things like renewed faith and sometimes astral drifts even.
Vs aggro, I look to bring in the wraths and thragtusk. I will usually cut a couple cyclers like the shefet monitor and cast out, possibly 1 renewed faith since you bring in additional lifegain anyhow.
Vs combo, you want to bring in your hatebears and the creatures to put pressure on them early game. Depending on the type of combo, your cuts will change, but don't be suprised if you want to cut astral drifts and renewed faith both.
Sideboard hands: The same general principle applies 2/3 lands, but depending on the matchup you might need to mulligan more aggressively for hatebears.
