"As I died, I rejoiced. I would see my family again. But then I woke up back on the battlefield. Back in Kamigawa. Back in hell."
—Kenzo the Hardhearted
As a disclaimer, while I absolutely adore this deck, there is no good reason to build a Yomiji, Who Bars the Way deck. NMot for a lack of power but rather because it is a warcrime that will make your opponents hate you. By nature as a CMC 7 creature Yomiji, Who Bars the Way requires substantial ramp to get to, once you get there it is absolutely oppressive if you can stick it. However, this only really works if your opponents don't know just how much of a threat Yomiji, Who Bars the Way actually is, otherwise you will get focused down and get knocked out of the game. However, if you are whipping out a deck like this against unsuspecting opponents you are objectively a bad person and will lose friends over it. Unfortunately this means while Yomiji, Who Bars the Way is really fun and interesting to both build and pilot, there is never a good situation to actually break it out.
Yomiji, Who Bars the Way's effect returns all other Legendary permanents to the hand when they die, and in a format where everyone will be running at least one Legendary permanent that they can easily access at basically all times, this makes it look like a bit of a group hug style effect. However, depending on how you build around it there are a few ways to absolutely abuse this effect.
The most obvious application of abusing Yomiji, Who Bars the Way is infinite combos. Phyrexian Altar and Ashnod's Altar are your main culprits here, as they let you sacrifice various CMC 1 or less Legendary creatures such as Hope of Ghirapur, Isamaru, Hound of Konda, Kytheon, Hero of Akros
, Skrelv, Defector Mite, Yoshimaru, Ever Faithful, or either of Mikaeus, the Lunarch or Omarthis, Ghostfire Initiate if you have a passive power and toughness boosting effect such as Elesh Norn, Grand Cenobite, Eldrazi Monument, Crovax, Ascendant Hero Caged Sun or Spear of Heliod. You can also use the effect of Helm of Kaldra to pay 1 while controlling Sword of Kaldra and Shield of Kaldra to create a Kaldra token which can again loop infinitely. You can then use the mana you get from sacrificing them be able to pay the cost to immediately cast them again, and then you can repeat this combo as much as required. In the case of Ashnod's Altar specifically you need a mana filtering effect to turn it into white mana, but most of those that are infinitely reusable convert 2 mana to 1 of the appropriate color, so the math works out. You can also do something simmilar with Krark-Clan Ironworks and Legendary Artifacts with converted mana cost 1 or less such as Eater of Virtue, Gerrard's Hourglass Pendant, Hope of Ghirapur, Lost Jitte, Luxior, Giada's Gift, Mox Amber, Mox Opal, Skrelv, Defector Mite, Stone of Erech, Tarrian's Soulcleaver, The Millennium Calendar, or The Ozolith. Deathrender can also allow any Legendary Creatures at all to be infinitely looped for this purpose as well. Regardless this allows for infinite triggers of various enter the battlefield, on cast, or death triggers such as Cathars' Crusade, Daxos, Blessed by the Sun, Martyr's Bond, Oketra's Monument, God-Eternal Oketra, or Bontu's Monument, and depending on what combination of the above cards you use, this can also net you infinite mana for whatever you desire to do with it. Another infinite combo of note is what you can do with Gideon, Ally of Zendikar, as by using his -4 ability he dies and goes back to the hand where he can be cast again, allowing for as many unremovable Emblems that grant +1/+1 boosts to your creatures as you could want. Eriette's Tempting Apple can also be used infinitely, allowing you to steal all their creatures to sacrifice off for effects, deal infinite burn damage, or gain infinite life.
Aside from infinite combos, Yomiji, Who Bars the Way also allows for quite a toolbox of various soft and hard board locks. Which in addition to being enabled by Yomiji, Who Bars the Way, many of the various combo pieces are also protected by it as well, making any attempt to break the lock even harder.
The simplest is by far Mindslaver, for which as long as you are able to pay the cost to cast it and activate it at least once in the same turn, you can guarantee that a player is basically out of the game. Considering that one of the advantages of a mono colored deck in commander is the ability to organically put out a ton of mana using cards like Caged Sun, this is comically easy.
Another powerful lock the deck can pull is thanks to the combo of Urborg, Tomb of Yawgmoth and Kormus Bell. By turning all lands into 1/1 creatures Linvala, Keeper of Silence prevents your opponent from tapping them for mana, basically knocking most decks out of the game on the spot. This also combos well with both Crovax, Ascendant Hero or Elesh Norn, Grand Cenobite to outright kill all your opponents lands, including those that are indestructible. In the case of Crovax, Ascendant Hero specifically, it is generally useful to run many Legendary Lands, as while he will also kill your lands, Yomiji, Who Bars the Way will salvage most of them and allow you to play them again later whenever you choose to bounce Crovax, Ascendant Hero to your hand with his effect. Regardless, all of the above lock opponents out of the main mana source in the game.
Hokori, Dust Drinker is another useful way of locking down opponents as you can use it to prevent your opponents from untapping, and then sacrifice it right before your turn starts so you can untap your lands. Then you can just play it from your hand again during your turn to continue the lock.
Yosei, the Morning Star can also be repeatedly sacrificed to deprive your opponents of untap phases all-together and tap down anything else they happen to have on the field that is left untapped.
However my personal favorite of the locks that work well in this deck is Possessed Portal. It is very easy to bait out your opponents artifact removal with big threatening Legendary Artifacts like Planar Bridge that happen to be Legendary and thus somewhat protected by the effect of Yomiji, Who Bars the Way. Then once you are confident that your opponents are out of appropriate removal you can stick Possessed Portal. As players cannot draw cards this will mean that your opponents will be unable to draw into any removal to get it off the field. As such you can take advantage of Yomiji, Who Bars the Way to recycle Legendary permanents so you never run out of things to sacrifice to the Possessed Portal, while your opponents slowly have to sacrifice their whole field and discard anything they have left in hand. You are also relatively unaffected by the downside of losing the ability to draw due to the absurd amount of search power available to you.
Speaking of search power, there is just barely enough available to you in mono white to be able to consistently search out whatever you need. An important thing to keep in mind is that you can use various searching effects to search other searching effects, which lets you perform search chains to get to any specific thing you need. Thalia's Lancers and War of the Last Alliance get any Legendary card, the prevalence of sacrificing effects to enable the deck as a whole means that Arena Rector and Academy Rector puts any Planeswalker or Enchantment permanent onto the field for you, Call the Gatewatch, Urza's Sylex, Ignite the Beacon and Djeru, With Eyes Open can find any Planeswalker, Citanul Flute gets any creature, Conduit of Ruin Sanctum of Ugin, and Eye of Ugin find the Eldrazi titans or various other big colorless creatures, Enlightened Tutor gets any Artifact or Enchantment, Flagstones of Trokair can be repeatedly killed off to put Plains onto the field as long as you control Yomiji, Who Bars the Way, Idyllic Tutor, Plea for Guidance, and Moon-Blessed Cleric searches any Enchantment, Inventors' Fair can be used repeatedly while you control Yomiji, Who Bars the Way to search out Artifacts, Kuldotha Forgemaster, Scrapyard Recombiner and Oswald Fiddlebender can repeatedly cheat any Artifacts out if you have Yomiji, Who Bars the Way to recycle Legendary Artifacts to pay the cost, Moonsilver Key finds any Artifact with a mana ability, Open the Armory finds any Aura or Equipment, Planar Bridge cheats any permanent from your deck onto the field, Planar Portal and Tamiyo's Journal searches any card at all, Pyre of Heroes can be used to grab various creatures from the deck albeit it is highly situational depending on how you build the deck, Ranger of Eos and Ranger-Captain of Eos directly find any of the CMC 1 or less creatures including the various combo integral cheap Legendary Creatures, Recruiter of the Guard has a similar function to the aforementioned Rangers of Eos and a bunch of cheap creatures, Search for Glory finds any Snow, Legendary, or Saga, Shield-Wall Sentinel has the potential for a few targets if you build around it, Shrine Steward can grab and Aura or Shrine, Skyship Weatherlight can search any Artifact or Creature but its a tad risky to use because anything exiled with it is gone for good ((although TECHNICALLY Pull from Eternity could be used to rescue essential pieces), Steelshaper Apprentice, Steelshaper's Gift, Stoneforge Mystic, Stonehewer Giant, and Taj-Nar Swordsmith search any Equipment, Tallowisp searches any Aura whenever you cast Yomiji, Who Bars the Way or the occasional Yosei, the Morning Star, Transmutation Font searches any Artifact, Urza's Saga searches various trinket artifacts, Heroes' Podium can grab Legendary Creatures from the top few cards of your deck, Horn of the Mark searches the top 5 cards of your library for a creature, The Mana Rig is extremely mana inefficient but does also search however many cards off the top of your deck as you can afford to pay for for any two cards, Weatherlight grabs any historic card off the top 5 cards of your deck, Wilfred Mott takes some time to get online enough to be particularly useful but searches any card with converted mana cost 3 or less from the top of your library, and finally Weathered Wayfarer and Expedition Map can find ANY Land. As you can imagine, so many tutor effects, many of which search each other, allow for incredible speed and consistency setting up mana ramp and whatever aforementioned locks or combos you would desire. Not to mention many of these tutors can be recycled and reused thanks to Yomiji, Who Bars the Way, or cards like Loran, Disciple of History, Reya Dawnbringer, Samwise the Stouthearted, or Teshar, Ancestor's Apostle which can be protected by the effect of Yomiji, Who Bars the Way.
Of course in order to take advantage of most of the deck's potential, there needs to be outlets for sacrificing certain permanents. Redrock Sentine, Rath's Edge, and Dust Bowl allow you to sacrifice Flagstones of Trokair and Gods' Eye, Gate to the Reikai to build some extra advantage in the process. High Market, Miren, the Moaning Well, Trading Post, Helm of Possession, Eldrazi Monument and the aforementioned Ashnod's Altar and Phyrexian Altar all help cycle through your Djeru, With Eyes Open, Loran, Disciple of History, Hokori, Dust Drinker, Mangara of Corondor, Ulamog, the Infinite Gyre, or Yosei, the Morning Star (just to name a few potential Legendary Creatures) to allow you to retrigger effects while building extra advantage.
Now keep in mind, this is all mostly just my brainstorming. The fact that its not a deck I feel I'd get any use out of means that I've not really put too much effort into actually testing for the most optimal build or ratios of the deck. If you do decide to not heed my warning and actually build this thing, I'd highly recommend iterating on my design. Use this deck profile as more of a template than a goal to aim towards, especially considering that I don't have the time to keep this whole thing updated with every new set! There are almost certainly going to be new things to consider as time goes on!
