"Boss Key — You need this key to open the door to the boss's room."
—The Legend of Zelda: Ocarina of Time instructions manual, page 32
In many video games, there are levels or worlds that conclude when the player finds and defeats a boss. Usually, the destination where the opponent awaits is a dedicated Boss Room, and depending on how the level is designed it may or may not be preceded by traversing a Boss Corridor. So in many cases, simply getting there is all it takes to start the grand confrontation.
However, there are cases where the door (or whatever entryway asset is present) is locked, and thus necessitates a key or some other kind of collectible to open it. The player may even need several units of a specific kind of item to open it. Thus, from the moment this Locked Door is spotted, the game makes it clear to the player that the relevant item(s) is/are required. While sometimes that item may have been located in an earlier spot and the player forgot to get it (or didn't even know it was there), in other cases the level is designed to make it so the door is found relatively early, and then the player continues progression as usual to eventually find what they need. In the case of a Collect-a-Thon Platformer, the entire level may be devoted to gathering all (or a sufficient minimum of) items for the desired purpose.
In an alternative scenario, the door may not be locked by itself, but it is guarded by someone who won't let the player pass unless they fetch an item for them (sometimes it's just money and it takes a bribe, but it can also be a unique item like medicine or a valuable treasure).
There are also cases where a Boss-Only Level is only reachable this way. Lastly, it's not limited to unlocking plot-critical bosses. There are also games where one or more Optional Bosses (including Superbosses and True Final Bosses, potentially) can be unlocked with the help of rare or well-hidden items.
Expect to see a large amount of recovery items close to the place where you have to use or deliver the item to reach the boss (though sometimes those may be placed in an intermediate spot connecting to the Boss Room).
A form of Instructive Level Design. Sub-Trope of Lock and Key Puzzle. Compare Cash Gate, Fame Gate and 20 Bear Asses, where it's more of a fee than a set of keys. For cases of triggering a boss by defeating standard enemies, see Kill Enemies to Open and Gotta Kill Them All (or Flunky Boss if the enemies are sent by the boss directly to kill the character). See also Already Undone for You if other characters seem to be able to get in ahead of you without the key. For cases when a special item isn't necessary to reach a boss, but can be used to alter the outcome and/or conditions of the fight, see Boss-Altering Consequence.
No relation to Boss Button, to which Boss Key redirects to.note
Examples:
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Action-Adventure
- Hollow Knight: The Love Key is needed to open the Tower of Love, where the Collector resides and can be fought, that guy who has been putting all the grubs in glass jars that you've been finding all around Hallownest.note
- Hollow Knight: Silksong: The Grand Gate to the Citadel is opened by ringing the bells in five bell shrines across Pharloom. However, doing so doesn't give access to the Citadel directly; Hornet must confront a boss, the Last Judge, first.
- The Legend of Zelda:
- The Legend of Zelda: A Link to the Past set the tradition in itself and subsequent installments of featuring, in addition to Small Keys to open regular Locked Doors, a unique (usually gold-colored) Big/Boss Key that opens the door leading to the Boss Room (in A Link to the Past itself, the Big Key is also needed to open the current dungeon's flagship item). In the case of Phantom Hourglass and Spirit Tracks, the key has to be carried manually by Link due to its weight, thus requiring careful navigation.
- The Legend of Zelda: Twilight Princess mostly has standard boss keys, but the second dungeon (the Goron Mines) and the fifth (Snowpeak Ruins) change the formula somewhat:
- The Goron Mines have the boss key split into three parts, each of which must be retrieved from a Goron elder somewhere in the dungeon. After this, it acts like a normal boss key.
- Snowpeak Ruins has Yeta tell the player where the boss key is three different times. The first two times are red herrings, leading to ingredients for Yeto's soup. Furthermore, the boss key is actually the key to Yeto and Yeta's bedroom, where the Mirror of Twilight shard is located, as it's not until looking upon the mirror that Yeta turns into the boss of the dungeon, Blizzeta.
- The Legend of Zelda: Skyward Sword: Instead of a traditional Boss Key, each dungeon except the last one has a uniquely-shaped object that has to be placed meticulously through a non-standard lock in order to open the door leading to the Boss Room. The position and arrangement of the object are done by moving and tilting the Wii Remote (Wii version) or right Joy-Con (Switch version).
- Metroid Prime 2: Echoes: The Dark Temple Keys serve the purpose of opening the contraptions that block the way to the wide halls of the temples in Dark Aether (which are the Dark World equivalents of the Luminoth race's temples), where huge, powerful bosses await. The first three temples (located respectively in Dark Agon Wastes, Dark Torvus Bog, and Ing Hive) each require three keys, which are shaped like multi-ringed artifacts with a glowing red nucleus); however, the Sky Temple requires nine (technically ten, but one of them was already put in its place prior to the events of the game), which look similar to the Dark Temple Keys, except their nuclei glow blue.
Action Game
- Killer7: The majority of levels in the game have Soul Shells (former gun bullets), which have to be gathered and then delivered to a mysterious man behind a payment booth so the Smiths can cross the Vinculum Gate and reach the main boss's whereabouts (in fact, a Mini-Boss in the form of a new type of Smile awaits them along the way as well). Subverted twice in the penultimate chapter, as in the first level they only find a Mini-Boss on the way and the person they are looking for went elsewhere (so the level ends immediately afterwards), and in the second level there's more to do in order to meet the boss (who turns out to be outside the main building where much of the level takes place).
Beat 'em Up
- As befitting a spin-off of The Legend of Zelda, Hyrule Warriors has several stages in Adventure Mode where you have to find a Boss Key in a certain keep to face the enemy commander, with them summoning a Giant Boss after being defeated. And the stages in question tend to be where the dungeons were relative to the game the Adventure Mode map is based on, with the location of the final dungeon or boss always having you fighting on Ganon’s Tower and facing Ganon himself before the credits roll.
- Mortal Kombat Mythologies: Sub-Zero:
- In Stage 8, Shinnok's Fortress, Quan Chi's three personal assassins each hold a key that allows access to the last bosses of the game.
- In every elemental stage, Sub-Zero has to find three keys of the elements (Wind, Earth, Water, and Fire). However, only one key is needed to open the room to the Water God in the Water Element stage, and three keys are needed to open the room to the Fire God in the Fire Element stage.
- River City Girls: The Optional Boss replaces the regular Final Boss if the player equips both the Mami and Hasabe Charms before entering the fight.
First-Person Shooter
- Borderlands: The main goal for the game is to assemble the Vault Key to unlock an ancient alien treasure vault, but it's actually letting something come out of the one-way Cool Gate, and the only loot are the Random Drops from the Eldritch Abomination-type Final Boss inside.
Hack and Slash
MMORPG
- RuneScape:
- Each of the Legiones can be found in their locked laboratories, which require a key to open; one is required for every killnote . The keys are randomly dropped by the mobs in the immediate vicinity, or can be purchased from other players.
- Fighting The Magister requires a key (which is dropped by monsters in the dungeon or purchased from players), but in a variant the key isn't actually consumed until the fight is initiated. The boss room cannot be accessed without one, however, so this is likely Gameplay and Story Segregation.
Party Game
- Mario Party 7: In the last board played during Solo Mode (Bowser's Enchanted Inferno), the player's character has to purchase a Star (which costs 20 coins) and then head back to the lava-surrounded central isle to challenge Bowser in the Final Boss showdown. If the character is defeated, then they have to buy another Star for a rematch, though the progression of the battle isn't reset. This is both a blessing and a curse: while it allows the player to resume the fight from the point when they were defeated, it also allows the rival character to buy a Star and then challenge Bowser (since the boss fight is the same for both contestants), thus risking the possibility of them picking up where the player left off and stealing the victory.
Platform Game
- Banjo-Kazooie: The Jiggies are typically used to unlock the main levels by completing their associated pictures. However, the last picture (not counting the secret one that doubles the Life Meter) has to be completed to reach the room from which the starring duo can reach Gruntilda, the Final Boss. Tellingly, instead of showing a location, the picture shows the full image of Gruntilda. Completing it requires 25 Jiggies, due to having a 5x5 size (all previous pictures were 4x4 in size and partially complete by default).
- Banjo-Tooie: There are two examples of bosses that are reached by gathering specific items themed around their corresponding worlds:
- Targitzan is the boss of Mayahem Temple. To get to the Mayan god of target shooting, the bear and bird have to collect statues shaped like him. By gathering ten, they can access a large regal chamber... that is empty (save for a Jiggy); but by gathering twenty, they can meet the real deal.
- To meet the "big main attraction" of the Big Top Tent in Witchyworld, Banjo and Kazooie have to find four tickets and give them to Conga (as a Double Unlock, they must also learn the Airborne Egg Shooting ability from Jamjars). The "big main attraction" turns out to be the world's boss, Mr. Patch.
- Bomberman Jetters: To unlock the True Final Boss (Dr. Mechadoc), it is necessary to collect all Lightning Cards from the Mini-Boss fights, and then face the said-to-be Final Boss (Ouryu). Doing this grants access to the Bomber World, a Boss-Only Level where Bomberman faces Mujoe and then the true mastermind, Dr. Mechadoc.
- Castlevania:
- Castlevania: Symphony of the Night: In order to open the gateway to the Reverse Castle Center and directly confront Shaft and Dracula, Alucard needs to explore the Inverted Castle to gather the five Vlad Relics (the Ring, the Eye, the Tooth, the Rib, and the Heart), and then head to the upside-down clock room in Black Marble Castle to proceed to the decisive opening.
- Castlevania 64: Just before the final boss, if the player has spent more than 30,000 gold at Renon's shop, his dialogue changes from just saying goodbye, into a notice that he's activating one of the hidden terms of the contact that was required to use his shop, and the player will need to defeat Renon to continue with the story.
- Castlevania: Dawn of Sorrow:
- Magic Seals are needed to open the doors of bosses that they're used on, thus doubling as Ability Required to Proceed, to make sure the player can actually end the battles.
- Doubling over as a means to avoid the neutral ending where Soma kills Dario in his second boss fight, the Paranoia soul is needed to enter the mirror in the room where the real boss, and Dario's source of power, is hiding.
- Crash Bandicoot: Starting with Crash Bandicoot 2: Cortex Strikes Back, accessing the Boss-Only Level that concludes a world requires collecting all five Power Crystals found respectively in the world's five standard levels; so even if those levels are completed, progression won't be possible without making sure to grab the crystals along the way. This is also a Justified Trope, as Cortex is aiming to periodically send his best creations (as does N. Brio at first in the second game) to defeat Crash and take away the crystals he's gathered so far; by the end of the game, with Crash (as well as Coco in the games where she's playable) having kicked the butts of those opponents, the only bad guy left is Cortex himself (thus placing him as the Final Boss after the last remaining crystals were collected).
- Donkey Kong 64: The standard bananas serve this purpose. Each world except Hideout Helm features a boss whose battlefield is accessed by opening a big wooden gate in the room of Troff 'n' Scoff. These two characters, despite serving as the gatekeepers, are on the good guys' side, and what Troff asks the Kongs to do is to feed Scoff with enough bananas for him to grow big and heavy so he can Ground Pound his standing platform and rise to the one Scoff is in. This allows Scoff to reach the silver lock above him to open it and, with it, the door. The number of bananas required varies depending on the world, but it does increase: it starts with just 60 bananas in Jungle Japes, and ends with 400 in Creepy Castle. For extra difficulty, to unlock each boss the Kongs can only feed Scoff with the bananas gathered in the current world, so the ones that remained as a surplus in previous worlds are useless.
- Sonic the Hedgehog:
- Sonic Unleashed: In the Xbox 360 and PlayStation 3 versions, the player must collect each region's Sun Key and Moon Key by beating their daytime Act 1 and nighttime Act 1 stages respectively. The keys then combine to create a Gaia Key that unlocks that region's Gaia Temple. The Wii and PlayStation 2 versions replace the keys with Planet Tablets that are acquired the same way and perform the same function.
- Sonic Generations: The Boss Gates for the first three bosses require three Boss Gate Keys, one for each Zone, which can be obtained by completing a Challenge in that Zone. The Boss Gate for the final boss, the Time-Eater, is unlocked using the seven Chaos Emeralds, which you acquire by beating bosses and rivals.
- Shadow Generations: Boss Gates return, but this time require you to win two Challenges per zone in order to unlock them. The first two require three Gate Keys to unlock, but Mephiles' requires four.
- Wario:
- Wario World: The Red Diamonds located in the levels are used to dispel the Stone Doohickeys (single-eye statues) that guard the entrances to the bosses.
- Wario: Master of Disguise: The Crimson Diamond is the only thing that can open the gate that leads to the room with the final fragment of the Wishstone. Wario explores the Allergia Gardens to retrieve the diamond after the Big Bad Carpaccio hid it. Upon finding it, he can open its door and confront Carpaccio... before the latter is Out-Gambitted by the actual Final Boss, Terrormisu (the true form of Tiaramisu).
Roguelike
- The Binding of Isaac: Accessing the Mega Satan boss fight requires the player to collect two pieces of a key by bombing the statues in two Angel Rooms and then defeating them. You can, however, use Dad's Key to bypass the lock without fighting the angels.
- Dead Estate: In order to access the boss room on each floor, you will first have to locate the boss key somewhere else on it in order to open the door. This is Played for Horror on the Old Set, as that floor is entirely empty save for the boss key and touching it prompts a Fission Mailed message, revealing it to be a trap set by the Static Demon.
Role-Playing Game
- Divinity: Original Sin II: Entering Lucian's Tomb, The Very Definitely Final Dungeon, requires either a scrupulously prepared player character or an amulet from the Tomb's creator, although the villains can somehow get in on their own. Justified because Lucian designed the tomb as a secure hideaway to fake his death and complete his schemes.
- The Elder Scrolls V: Skyrim: In the Dragonborn DLC, the ghost of Karstaag can be challenged in a Superboss battle by finding his corpse's skull and then placing it in his castle's throne. The skull, in turn, can be collected in the Glacial Cave on the northern coastline of Solstheim. The fight, obviously, takes place in the throne room.
- ENDER MAGNOLIA: Bloom in the Mist: To enter the Central Stratum, and fight the boss that blocks exploration of Central shortly after entering, the 3 Attuners in the Lower Stratum have to be gathered to repair the Grand Lift to Central.
- Etrian Odyssey:
- Etrian Odyssey IV: Legends of the Titan: There's a sidequest available during the Playable Epilogue ("the Ominous Gale") where the player's character party assembles a special artifact from pieces guarded respectively by the main civilizations (humans in Tharsis, Vessels in the Scarlet Pillars, Sentinels in Sacred Mountains, and the humans from the Empire). The resulting object is the Omnikey, which can be used to open a door in a Mini-Dungeon (Moth's Garden) and access a room featuring a secret boss (Iwaoropenelep, from the first game in the series).
- Etrian Odyssey Nexus: The boss of Undersea Grotto, Ketos, plays with the trope. His door is actually not locked at all but, by the time the player's character party has reached it (shortly after getting to the stratum's lowest floor), they aren't yet given permission to proceed to the end since their objective is to gather all ancient scrolls documenting the story of Lemuria. Thus, they have to find them by exploring the rest of the floor (plus, at one point, backtracking to a previous floor after turning off the Roaring Rapids that made one of the scrolls inaccessible before). Once they manage to do so, they can give the scrolls to a character outside the dungeon and then receive the OK to conclude the exploration, thus allowing them to enter the final door and challenge the boss.
- Fable: To reach the Final Boss, the Hero needs to collect three specific souls for the mechanism that unlocks the Bronze Gate at the furthest extent of the Grim Up North. Given that the opening of the Gate is a Sign of the End Times, it's ambiguous whether the Hero's releasing a Sealed Evil in a Can or taking the fight to the villain before it has the chance to break out, but he wins either way.
- Hades: The door out of the underworld, leading to the final boss fight against Hades himself, is guarded by Cerberus. Zagreus has to search the nearby tunnels for a Satyr Sack he can use to bribe Cerberus to let him through.
- MARDEK Chapter 3:
- The chest containing the Red Dragon Scales, which is guarded by the Red Dragon, lies behind a door unlocked by the Little Wooden Key, which can only be obtained after a rather long Chain of Deals.
- While Castle Goznor is accessible as long as the Dark Temple (the final dungeon in the initial complex) is cleared, which unlocks access to the world map, Rohoph will not let you proceed past the door to the Final Boss until the Water, Fire and Earth Crystals have all been collected.
- Persona 5: While the boss room of the seventh Palace can be easily accessed from the starting point, the Phantom Thieves need to collect five letters of recommendation in order to gain access, which can be acquired by finding the cognitive counterparts of the Palace Ruler's confidants and defeating them in battle.
- Pokémon: Several legendary Pokémon are associated with a special item, which is frequently required to access them in their games of origin, as well as in later appearances.
- Pokémon Gold and Silver:
- Ho-Oh and Lugia have two such items: the former has the Rainbow Wing and the Clear Bell, while the latter has the Silver Wing and the Tidal Bell. In their original appearances, the respective Wings are required to progress past a certain point in the Tin Tower (Bell Tower in the remake)/Whirl Islands; while in the remake, the Bells are also required to summon them (at least in the games they served as mascots of; the Bells were not required when you attempted to catch Ho-Oh in SoulSilver or Lugia in HeartGold).
- Pokémon HeartGold and SoulSilver: After defeating Red, you can obtain the Blue Orb (in HeartGold) or the Red Orb (in SoulSilver), which will cause Kyogre/Groudon to appear in the Embedded Tower. Having both of them in one game will allow you to obtain the Jade Orb, which will allow you to face Rayquaza at the same location.
- Pokémon FireRed, LeafGreen and Emerald would make Ho-Oh and Lugia accessible again at Navel Rock, which you could only reach by obtaining the Mystic Ticket through a now long-past timed distribution.
- Pokémon Ruby and Sapphire:
- Groudon and Kyogre are heavily associated with the Red and Blue Orbs, respectively, those being the items used to awaken them.
- Pokémon Omega Ruby and Alpha Sapphire has a sidequest where you can obtain one of the bells (The Clear Bell in Omega Ruby or the Tidal Bell in Alpha Sapphire) by obtaining the Scanner and giving it to Captain Stern. This allows you to capture the associated Legendary Pokémon (Ho-Oh with the former, Lugia with the latter).
- Pokémon Black and White: Reshiram and Zekrom are both initially in dormant forms as the Light Stone and Dark Stone, respectively. N unseals one of them (The one not serving as the mascot of the version you're playing), while you will eventually unseal the other.
- Pokémon Brilliant Diamond and Shining Pearl: Pal Park from the original version and Platinum is replaced by Ramanas Park. Here, you can exchange Mysterious Shards excavated from the Grand Underground for special Slates, which will grant you access to various Legendary Pokémon:
- Using a Johto Slate, Raikou, Entei and Suicune can be found in the Johto Room in Brilliant Diamond.
- Using a Kanto Slate, Articuno, Zapdos and Moltres from the Kanto Room in Shining Pearl.
- Using a Rainbow Slate, Ho-Oh can be found in the Rainbow Room in Brilliant Diamond.
- Using a Squall Slate, Lugia can be found in the Squall Room in Shining Pearl.
- Using a Genome Slate, Mewtwo can be found in the Genome Room in both versions.
- Using a Discovery Slate, Regirock, Regice and Registeel can be obtained in both versions.
- Using a Soul Slate, Latias and Latios can be obtained in the Soul Room.
- Using an Oceanic Slate, Kyogre can be obtained in the Oceanic Room.
- Using a Tectonic Slate, Groudon can be obtained in the Tectonic Room.
- Using a Stratospheric Slate, Rayquaza can be obtained in the Stratospheric Room.
- Using a Distortion Slate, you can face a Lv. 100 shadowy Giratina in the Distortion Room. You cannot catch it, but winning this fight will allow you to obtain the Griseous Orb, the item that allows Giratina to assume its Origin Form when held.
- Even beyond the realm of Legendary Pokémon, there are examples of this for major human trainers.
- In Pokémon Red and Blue, its remake and ''Yellow'''s reimagining, the first city you'll visit after leaving Pallet Town is Viridian City, which has a Gym. However, the Gym is locked; you can only challenge its Leader, Giovanni after you've defeated all the other Gym Leaders in the region and obtained their Badges.
- HeartGold and SoulSilver: Once you get to Kanto, you can challenge the Gyms in practically any order you want, but Blue will not return to the Viridian City Gym until you speak to him at Cinnabar Island after obtaining all the other Badges. Interestingly, this was not the case in the originals; he would become open to challenge as soon as you spoke to him, regardless of how many Kanto Badges you had at the time.
- Pokémon Gold and Silver has Jasmine, who isn't there for the player to challenge until a quest to retrieve medicine is completed. Her gym is a straight path to her, lacking any Gym Trainers to battle in the original version.
- Pokémon Ruby and Sapphire has a similar situation to the Viridian City Gym in the Kanto games; one of the first cities you'll visit, Petalburg City, has the Gym run by your father, Norman. However, he's actually the fifth Gym Leader you'll face; you must first defeat Roxanne at Rustboro City, Brawly at Dewford Town, Wattson at Mauville City and Flannery at Lavaridge Town and obtain their badges before you can come back to face him.
- Pokémon Diamond and Pearl: Hearthome City is the third location with a Gym you visit in your journey, but Fantina is the fifth Gym Leader you will fight; you have to go obtain the third and fourth Gym Badges from Maylene and Wake, respectively. This is subverted in Platinum, however, as the order has been rearranged; instead of having to defeat Maylene and Wake first, then return, you can now fight Fantina when you first arrive at Hearthome City.
- Pokémon X and Y: Lumiose City is visited earlier in the journey, and has a Gym, but you won't face it until much later. You must first defeat Grant, Korrina and Ramos and obtain their Badges, then you'll end up returning to face Clemont for your fifth Badge.
- Pokémon Sun and Moon and Pokémon Ultra Sun and Ultra Moon: Instead of having a traditional Gym system, the Alola games have the Island Challenge, where you travel around each of the four Islands, completing various Trials, each ending in a battle with a Totem Pokemon. Some of them have their own examples of this trope, such as Mallow's Trial (Which sees you gathering ingredients for a stew that will lure out the Totem Lurantis), or Mina's Trial in the Ultra games (Where you must travel the region, defeating all of the Trial Captains and gathering petals to assemble the Rainbow Flower, which will summon the Totem Ribombee).
- Pokémon Sword and Shield has two different cities you visit before facing their respective Gyms. The first is Motostoke, which you'll visit for the opening ceremony of the Gym Challenge, leave to obtain your first two Badges from Milo and Nessa, then return to get your third from Kabu. The second is Hammerlocke, which you'll visit after obtaining your first three Badges, but will have to revisit after obtaining the next four to challenge Raihan for your eighth and final one.
- Pokémon Gold and Silver:
- Tales of Arise: In the Autelina Palace (Revisited), you must find the Duplicate Lord's Quarters Key to reach the boss, Ganabelt Valkyris. The key is obtained by exploring the office, reading notes in the meeting room, and finding it in a cabinet.
- Vampire: The Masquerade - Bloodlines: One half of the Big Bad Duumvirate, Ming-Xiao, apparently uses her Wrong Context Magic for home security as well as combat. Her boss fight requires you to retrieve four heavily guarded statues from opposite corners of the innermost level of her temple, then arrange them in a central chamber to activate a portal to her private sanctum. There's no exit, but thankfully, killing her opens a return portal.
Sandbox
- Valheim: Forsaken altars are randomly distributed across biomes, with their locations being revealed via Vegvisir stones also randomly found in dungeons and structures. Once you find one, you only get a vague hint as to what kind of item you need to sacrifice to summon the Forsaken, but it's something connected to the Forsaken (deer heads, greydwarf seeds, dragon eggs, etc.).
Tabletop Game
- Tomb of Horrors: Adventurers can only unlock the Secret Path to the true crypt of Acererak with a sequence of two keys that are hidden elsewhere in the dungeon, one of them dismantled. Justified as Acererak built the whole dungeon as Schmuck Bait for adventurers; he only wants to be personally disturbed by those whose souls are worth eating.
Third-Person Shooter
- Jet Force Gemini: Normally, a boss is reached after simply getting to the end of its world (though that already requires killing several enemies along the way). However, to open the door that leads to the Dual Boss in the Eschebone (the Mechantids), it's necessary to find the Magenta Key, and much of the level is traversed to locate it (since the door requiring it is found early).
- Warframe:
- In order to fight Ambulas in its Assassination mission on Pluto, each player must pay 5 Animo Nav Beacons, which in turn are earned by beating field boss versions of Ambulas on the same planet.
- In order to fight Kela De Thaym on Sedna, one must pay 25 Judgement Points, which are earned in the Arena missions found on the same planet.
- Mutalist Alad V's fight requires a Mutalist Alad V Key. The (reusable) blueprint is a reward from the Patient Zero quest, and each key also requires Mutalist Alad V Nav Coordinates, which are Battle Pay for Infested invasions.
- In order to fight Nihil, both Nihil's Oubliette (a decoration) and an "Enter Nihil's Oubliette" (one-time) key must be purchased from the Nightwave Cred shop.
- The first part of the Assassination mission for The Fragmented involves picking up 30 eyes that spawn after you protect an objective for a while. Picking up 60 instead opens up its Superboss version, The Fragmented One.