Game Breaker / Library of Ruina

Strategies

• All three of the "Floorxodia" strategies can break the game wide open. Floorxodias are a Fan Nickname to incredibly powerful strategies specific to certain floors and can only be played if specific Abnormality Pages show up to draw. There are commonly agreed to be three of these: Netzxodia, Tiphxodia, and Binxodia.
• Netzxodia can be activated if Netzach stacks a ton of stagger recovery (such as the "Mind Hauler" passive) and draws Spring's Genesis. Each turn, a random enemy gets the "Petal" status effect: if that enemy gets hit 4 times during that turn, everyone gets Stagger damage, but the Librarian that equipped the page becomes untargetable during the next turn. If only that Librarian is left on your team, it means that the enemies cannot play cards or defend themselves in any way; which means that it's extremely easy to hit the Petal-affected enemy four times and re-activate the effect for the next turn, and the next, and the next... The only drawback is that this tactic makes you take Stagger damage each turn, but this can be countered with the right pages and effects.
• Tiphxodia requires Tiphereth to draw four pages first. These pages are Hate, Despair, Greed and Wrath. Each one gives her some kind of powerful bonus, but with a severe downside. As an example, Hate increases strength and reduces card costs on clash loss, while Wrath makes a librarian uncontrollable but buffs their Strength, card draw, and light gain. Once all four cards are assembled on one librarian, you draw the fifth and final one: Nix. This page removes all the downsides from each of the previous four cards and drops a disgusting debuff cocktail of 5 Feeble, Bind and Disarm onto your opponents. The combination of buffs for you and debuffs for your enemies all but guarantees victory outside of a select few scenarios.
• Lastly, Binxodia ^note  Also named Eggxodia or Birdxodia requires a similar situation as Tiphxodia: three abnormality pages dropped on one unit, before a finale page causes a huge power boost. For Binah, that's the Small Beak, Big Eyes and Long Arms pages, topped off with The Beast. This gives a huge amount of amazing effects to Binah. The components themselves provide a nice array of effects to start - in particular, Long Arms makes the user immune to nearly all damage over time effects and Big Eyes gives them a +1-2 in clashes while letting them recover HP and Stagger when winning clashes, albeit at the cost of all enemies prioritizing them for attack and dealing bonus damage to them. As for the final page, it fully restores the user's Light each turn while causing all enemies targeting or being targeted by the user to be both unaffected by power gain or loss and have their minimum and maximum rolls lowered by three. This is a lot, but to break it all down, Binah essentially gets the ability to attack everyone who targets her with a minimum of +7 Power thanks to the stacking effects while also completely nullifying all of their buffs. The full Light recovery each turn is just the cherry on top, letting the user spam high-cost pages like E.G.O. like they're nothing. The only downside is that all allies take 15 damage a turn, but that's a small price to pay for supercharging a unit to the point where they can solo pretty much any fight in the game.

Floors

• Keter is just a generally strong Floor with no real gimmicks or tricks and pretty good for a starter location. The Floor has Abnormality cards for inflicting debuffs (Pale Hands, Sword of Frost), buffing their own units (Scars and Fervent Beats), as well as more unique things like card manipulation (Learning and Lies). Keter's effects are useful in a wide variety of circumstances, giving the floor the ability to scale quite nicely into the lategame. Keter also becomes one of the three floors with an exclusive Patron-only keypage; that being the Black Silence's keypage, which becomes permanently equipped to Roland after beating Olivier and turns him into a fierce Master of All. You can either drop all your buffs on Roland and watch him carry, or spread your buffs out and make the entire floor into a dangerous place for your enemies to be.
• Hokma's Floor is built around Block and Stagger, with some very powerful deck synergies available exclusively to him. While Block dice are generally less effective than just straight up attacking due to the Clash mechanic, Abnormality pages like Attention and Focus, Marytr, Advent and Baptism can make it very difficult to get through Hokma's wall of block before your enemies get staggered and burst down the following turn; the Lean, Bloody Wings Abnormality page in particular removes this limitation entirely by letting Hokma's deflects directly deal HP damage ^note  That said, this page becomes even better when glued to Attention and Focus, that essentially doubles this effect , which combined with the floor's very high defensive rolls translates into very heavy damage on anything that tries to challenge them. That's right: you can have defense hit like a truck. This strategy has given him the nickname "Blockma", and it is very effective when built around properly.
• Binah's Floor meanwhile, is a lot more complicated - she focuses around redirecting aggression and messing with speed dice to funnel enemies towards a single extremely buffed-up ally. Cards like Eternally Lit Lamp, Punishing Beak, Tilted Scale, and Salvation make it very easy to mess with the enemy turn order, which can in turn allow you to brush aside their most dangerous attacks by redirecting them. This is augmented via Binah's own unique deck and pages which place heavy emphasis on removing enemy attacks or speed dice, as well as the Fairy mechanic for added damage. Clever use of Binah's floor can destroy any opponent by completely messing with their intentions and rigging things in your favor. Once her Realization is complete, she also gains access to the extremely powerful Apocalypse Bird pages that can either heavily debuff a single enemy, buff your entire team, or turn one librarian into a nigh-unstoppable killing machine.
• Chesed's Floor has Abnormality pages that are all fantastic light generation sources, and his higher tier pages can be very powerful ways to spend expensive attacks without worrying too much about your light running out, such as Power of the Past, A Warm Heart, and Magic Trick. This makes it easy for Chesed to spend high-cost pages or Mass Attacks very frequently once he gets set up properly. One of the cards the Floor gains after Realization, Emerald, takes two dice that the enemy has played pages on, and turns them off. As Emerald returns into the deck, and it also gives a funky gadget in the form of additional Light restore if the librarian hits the affected enemy to faciliate its cost, hard fights with annoying enemy moves can possibly become much easier to clear.
• Gebura's Floor begins as one of the weaker floors until The Red Mist is completed, at which point the effectiveness of the floor jumps up several tiers. The gimmick of Gebura's floor is powering up one librarian via pages like Vengeance, Instincts and Shell, before dropping the powerful Mountain of Corpses on your flagship unit, which buffs them to kingdom come at the cost of killing every other librarian in play. This is most effective on the Patron Librarian Gebura, since she gains an exclusive keypage designed to synergize extremely well with her floor and this specific tactic. Gebura is so strong in this state that this floor was heavily nerfed from its original incarnation back in Early Access, and she's still arguably the strongest floor in the game anyways.
• Netzach's Floor prefers to slowly whittle down his foes. Netzach's Abnormality Pages all revolve around recovering health or stagger, while also doing things like lowering the stagger resistances of his enemies. Pages like Token of Friendship and Laughing Powder can make your librarians surprisingly tanky, while Ever-Repeating Performance can outright save an entire unit from death if played at the right time. It has also a focus on Pierce attacks, with Tentacles and Thorns working well with eachother as they can stagger a target rather quickly. He also has two powerful strategies available in difficult fights- he can either go for a Cheese Strategy setup with Spring's Genesis or play The Finale to debilitate his foes and drain their light almost completely.
• Hod's Floor focuses around mass debuffs with a particular emphasis on Bleed. Many of Hod's best Abnormality Pages specialize in dishing out loads of status effects that slowly whittle down your opponents' fighting ability. If you choose to roll the dice, then Hod can load up on powerful RNG powers like Funny Prank and potentially steamroll... if you can get lucky enough. Today's Expression in particular is unlocked early and if you activate the battle phase on its angry expression, the equipped ally can easily go ham the entire fight if you pay attention to its 'mood'. The sheer consistency with which Hod can wash down her foes in debuffs makes her surprisingly effective, though she does lose a bit of strength due to her reliance on Bleed. Because Bleed loses prominence in the midgame to make room for Charge, Smoke, and Singleton, one of Hod's major focuses becomes weaker for a time. Thankfully, Bleed gets some nice pages in Star of the City to make up for this. She also has insanely good E.G.O. at her disposal.
• Yesod's Floor is one of the most popular after Gebura's Floor post- Red Mist unlock, and not without reason. It focuses around stacking heavy amounts of blunt damage and debuffing singular opponents. In particular, Metallic Ringing inflicts Paralysis on every successful blunt hit, which can quickly snowball into your enemies' speed dice dropping to much lower values while your own skyrocket - it also synchronizes highly with Lament, which gives power if the enemy has a status effect. Other cards like Rhythm, Coffin, and Request (which also greatly speeds up farming) can destroy a target very quickly with massive amounts of power stacking, making Yesod effective in breaking stagger and keeping his supply of light filled, and the pages of the Little Helper also assist in avoiding bad dice rolls by gaining Haste, extra light and extra damage. On top of all of this, Dark Flame massively amplifies Yesod's already towering damage by turning enemy resistances into weaknesses (albeit also doing this for your Librarians), which has the potential to break fights that rely on conditional vulnerability wide open, as you can now just attack with impunity and kill the targets way earlier than intended. The floor also has some nasty E.G.O. at its disposal - Regret is an almost guaranteed stagger on a single unit while Harmony can deal tremendous damage while providing Strength, and Solemn Lament is possibly the strongest E.G.O. page in the entire game, capable of completely destroying almost any enemy with a single use when combined with Yesod's buffs. The fact that this Floor is realized early makes it so that it can carry its weight on full strength pretty fast.
• Malkuth's Floor rounds out the game as probably the least Game-Breaker Floor, but she too has a lot of tricks up her sleeve. She has a lot of emphasis on "revenge" mechanics as well as Burn, although this is more of a failsafe that other Floors lack, and it's not to say that Malkuth's Floor lacks an offensive side - as the Floor also has some very strong cost-manipulation strategies, with Xiao's Fervent Emotions combined with Happy Memories being among the most infamous. The status effect of Burn in general has a dying efficiency once one unlocks other mechanics like Smoke, Charge and Singleton, but it makes a return with the Liu Association and their emphasis on Burn, which make them good competitors- Xiao's page is almost tailor-made to use with Malkuth's floor. The Floor has also self-sustain with Gluttony and The Fairies' Care, something which Malice rewards you for.

Keypages

• Yujin's page is considered as one of the best pages in the game, despite being a mere Urban Nightmare page. First of all, the passive Eye of Death/Enervation will give all Dice a +1 Power gain, which is small, but in certain circumstances, makes a difference in rolling your dices. Secondly, her Extreme Fatigue passive where librarians equipped with it begins the battle with only 25% of their base HP remaining can be a blessing when being paired with cards that become stronger and add additional effects when being used by a character with less than 25% HP such as Tomerry's Faint Memories and Gebura's Abnormality page Ruddled Welts. When paired with Lyla's Health Hauler passive, you can easily heal your HP every time you attack enemies, which can make you heal to well beyond 100 HP (out of Yujin's base HP of 288) in long battles, and even her sealed third speed die is equipped with a defensive page that can protect you if someone goes after it. And to top it off, her page comes with an exclusive card Boundary of Death —- a 4-cost page with a 1-4 die that can roll 50+ attack when it rolls a 4, guaranteeing a large HP and Stagger sweeper hit.
• A Star of the City page, The Purple Tear. Her page comes with four decks instead of one, which you can switch in-between for 1 Light with a cooldown of 2 Scenes, divided between Slash, Pierce, Blunt and Guard. On top of giving a +1 power bonus for the respective die type on the first Scene after switching decks (and a persistent +2 power bonus) it also comes with various effects ranging from +50% damage dealt (slash), doubled ailment inflicts (pierce), +50% stagger damage dealt (blunt), and immunity to status ailments (guard). Her page is extremely versatile and can benefit from any setup, while the boss fight itself also gives you powerful cards that synergize well with the key page's passives.
  • For that matter, you can use Overcharge without any consequence on the Guard deck, making her extremely good with charge-based decks as the card's only major drawback (inability to fight the next Scene) is gone.
• The Floor of Language becomes extremely powerful once you acquire The Red Mist's page, which comes with extreme self-sustainability (dealing enough damage with any of the three cards will reduce the Light cost of all other copies of the card by 1 until the Light cost becomes 0), extremely powerful dice, the potential for massive amounts of power stacking (activating her E.G.O. alone will give all dice +2 power along with another +1 for every enemy slain), an infinity speed dice to target whoever you want, and both an extremely powerful single-roll attack alongside a strong Mass Attack for staggering multiple foes at once. Attributing "Myo's Prowess" to the Red Mist's page will cause all her infinity speed dice to be guaranteed to gain +5 power against any other speed dice, giving a huge power-spike to an already-powerful page. One can boost this page even further with some of the Abnormality Pages of this floor, which all synergize with it by granting even more power buffs and sustain - in particular, Mountain of Corpses gives some incredible buffs at the cost of killing all other Librarians in play, while all three of the Nothing There pages are straight up broken. You can either become completely immune to stagger damage, recover HP depending on the damage of your first dice, or double the power of your last die played. Suffice to say, players who are struggling in Star of the City tend to rely on this floor as a crutch, and for damn good reason.
  • The combo of "Myo's Prowess" and "The Strongest" from The Red Mist's page works incredibly well on Floor of Technological Science. Taking the Chained Wrath Abnormality Page^note Grants blunt power at the cost of fixing all Speed Dice at 1 will turn every die into an infinity die with +5 power ^note  This is because The Strongest searches for the slowest speed die, which all die will become when they're under the effects of Chained Wrath. Thus it turns every die into infinity die.. Add Clean^note Grants power equal to the speed advantage compared to the target, up to +3 and that's +8 power on all dice, all of which can be further increased with more buffs from other Key Pages or Abnormality Pages. The only downside is that Yesod lacks the self healing Gebura's floor has and attributing The Red Mist prevents you from utilizing Gebura's full power, although that could be fixed with some pages and passives like Mind/Health Hauler (and if everyone else is dead, you won't need healing anyway).
• Nikolai's page, especially with Smoke infliction somewhere in the same party. Party-wide passive +1 Strength and Endurance on a fairly easy condition (maintaining 11+ Charge) does wonders for helping with clashes and offsets the dice boost at high Smoke, while pairing Smoke and Nikolai's target-marking passive more than doubles damage dealt to that target for the entire party, allowing for ripping through fights much faster than usual. Overall very solid party support for a Star of the City page.

Pages

• The seemingly unassuming card Combat Preparation, which you can get as early as Urban Legend, is very likely going to be a mainstay on any defensive builds you make in the future, and fits 'Blockma' to a tee. While its dice rolls are nothing to write home about, to put it lightly, its true value is that it gives all allies 2 Endurance next turn just by using it. Endurance, by the way, buffs all defensive die by its number, so all allies essentially gain 2 extra power to their defensive dice the next turn. This also buffs the dice of the card itself, since it has two defensive ones. Since it's not of the highest tier, you can use multiple of these cards at the same time, which means that if you slot them in on faster dice, you can stack this to kingdom come. Notably, this card is also unaffected by Pluto's Contract of Might. If you let everyone play it on two dice, and two librarians on a third, you can reach as much as 24 stacks of Endurance. This way, filling your decks with 3 copies of this card remains a viable strategy all the way into endgame, as long as you bring the maximum librarians allowed for that stage. Really, it is just best summarized in this meme◊.
• When you first get Overcharge, it kind of sucks. It's a real hail mary of a card, but comes with incredible downsides. Three incredible attack dice plus a Block counter dice for good measure, and you gain 10 Charge?! It sounds too good to be true- and it is. The card Immobilizes the user their next turn, essentially stunning them after using it. Enemy encounters are balanced around bringing the maximum amount of possible units at all times, meaning using Overcharge at the wrong time spells doom for your run attempt. Unless you're running the Purple Tear's Guard Deck, which nullifies all status effects. Suddenly, you can spam Overcharge and endlessly loop your deck with Leap and deal great damage with Ripple.
• Sharpened Blade is Simple, yet Awesome. Two 1-3 Slash dice and 4-5 Block dice on a 2 cost card sounds pretty terrible, but Sharpened Blade's effect is what makes it so strong. All Slash dice gain +2 power on the turn its used, which turns those 1-3 Slash dice into 3-5 Slash dice, which are decent. However, this effect stacks and its a rare card, meaning two pops of a Sharpened Blade boosts your Slash Dice by +4, turning those 3-5 Slashing dice into 5-7 Slashing Dice. Then you add on Bamboo Hatted Kim's Swordplay of the Homeland, and suddenly all your Slashing Dice sit at +6 power. This strategy is very expensive by the time it becomes available, but has amazing stability into even the lategame as Slash cards often deal very high amounts of damage. Violet Blade doubles the amount of power affecting the card, which can cause it to be a powerful single-target nuke, and that's just one example. As one final tip, this strategy has wonderful synergy with Hod's floor: Abnormality Pages like Axe, Alertness and Gooey Waste let a Slash user steamroll pretty much anything that comes their way.