The human brain contains: Flora (cerebral blood supply system, Willis), Ebrietas (medulla oblongata, brainstem, diencephalon, limbic system, arteries and veins). Rom, Arañas, and Reina Yarnham (the three meninges: dura mater, arachnoid mater, and pia mater). Lunar Lake (cerebrospinal fluid), etc.

2/2

The One Reborn I also know very little about. Too little to confidently say anything, sorry.

Paarl is a Darkbeast - I don't know if they're created from some special blood, perhaps a strain taken from Loran dungeons as you suggest. We know it isn't the only one, as the eccentric hunter Archibald designed his tools to generate "the same blue sparks that blanket a darkbeast". Also, the Beggar turns into one (no idea why) and there's more of them in the Loran dungeons.

Logarius is pretty straightforward. More interesting is why the Vilebloods' "corrupted blood" is so despised, but I'd have to read up on their lore to make any guesses.

Amygdalas don't really serve a purpose in my opinion, they're just minor great ones who chill in Yharnam and some higher dream realms, like the one in nightmare frontier does, or the dead one in the hunter's nightmare used to. There was a theory that they're sort of a single "hivemind" great one with multiple manifestations, explaining why Patches refers to a single "Amygdala".

Celestial Emmisaries might be a "successful" version of the living failures, essentially a product of the Church's experiments aiming to elevate humanity through other means than blood, to make contact with the Cosmos (hence "celestial emmisary"). Iirc, the Choir was established after the Orphanage, stemming from it, but it's still possible that they did continue taking in children to experiment on them, as I think the author of "the paleblood hunt" suggested. How did they get to the forbidden woods? Could be some escaped from Iosefka's Clinic after the choir impostor took over and turned the patients into these wobbly smurf shroomies. Why is one of them bigger? Maybe they function like a hivemind, too, and channeled more strength into one of them when in danger? Who knows.

I'm not even going to pretend I understand anything about Ebrietas or the Altar. Pretty cool that there's a God under the Grand Cathedral though.

Micolash is the head of the School of Mensis, transported in a ritual from Yahar'gul into a higher nightmare realm. There's some cool lore regarding the school's use of mercury and lighting in this, check out the Tarnished Archeologist's video about it on youtube. The School is sort of an ofshoot of Laurence's Healing Church that set up in Yahar'gul and started doing their own stuff there - or "nightmarish rituals", as the game says. It does seem they know about and are trying to get to Mergo or at least that their rituals "crave a newborn" - but this is too close to the lore I know little about - the One Reborn, the physical/metaphysical form of Great Ones, the goals of the Moon Presence, her relation to Mergo and his role in the Hunt, etc. Micolash doesn't seem to know his body in Yahar'gul is fried, so he just thinks he'll wake up when we kill him because he's bloody mad.

I think Mergo is specifically the child of Yharnam, ripped from her womb ages ago. Fair warning, the following is heavily headcanon. I think in the time of the Pthumerians, the Queen would be a woman "blessed" with child by the Great Ones, who desire children but always lose them/cannot have any themselves. For some reason, the Pthumerians eventually ripped the child from Yharnam's womb - I like to think they wanted to consume it, its umbilical cord, and its blood for power, and that's when the Great Ones cursed their own blood to turn lesser beings into "beasts" that inevitably succumb to bloodlust and beasthood, sort of ironically representing the Pthumeru "original sin" - we know Great Ones can punish whole races unto eternity for grave sins, as Kos curses all hunters to end up in the Nightmare after her child is, similarly to Mergo, ripped from her womb and slain by Gehrman, Maria, and other old hunters. Anyway, since Great Ones aren't restricted to their physical form, Mergo survives as an eternal infant. Why does the Moon Presence seem to guide our hunter to him, ending the Hunter's Dream when he's slain? How did the Dream end for other hunters like Djura or Eileen if they never reached Mergo? I don't know.

You got Gehrman lore right, imo. There's theories on how exactly he ended up in the dream in the first place, but it's late where I'm at and it's not terribly relevant so I'll skip that stuff.

Actually, I might continue tomorrow and write what I think about the Moon Presence.

1/2 - For whatever reason, reddit isn't allowing me to post a longer comment, so I'll paste the rest into a new one.

Alright I'll give this a go with my current ideas, but keep in mind that a lot of the fun with Bloodborne lore is its openness to interpretations and headcanons

Cleric Beast probably isn't sentient anymore, so it's not so much "guarding" CW as it is just hanging out there. Clerics turn into the most horrible beasts, so it makes sense for that boss to be near the Church's land. I'm not aware of any further backstory for this particular beast.

Gascoigne came to Yharnam a long time ago from another land and church, likely to cure some sickness he had with the Healing Church's famous blood. I don't remember the timeline here too well, but at some point he befriended Henryk, started a family with Viola and had two daughters, and was a black hunter of the Healing Church (read their attire descriptions for lore on the differences between black and white HC members). As all hunters are cursed to, he inevitably caved into bloodlust and beasthood, either before Viola went to find him (meaning he then killed her) or after she was killed by other beasts. We encounter him as he starts to go mad, and witness his full transformation.

Blood Starved Beast is also I think not sentient and just hangs out in the abandoned church. I don't really know why it's blood starved and flayed - maybe it was captured, mutilated, and crucified like the other one we see in the big building under Djura's tower, and just managed to escape later somehow. Maybe its blood was drained as it hanged (hung?) for the Yharnamites to drink.

Vicar Amelia seems to be using the pendant to resist her beasthood, which I think sorta builds up inside her and eventually overflows the pendant's protection, breaking into a sudden, monstrous transformation (like a river bursting through a dam). The pendant, passed down among the vicars who head the HC, is a reminder of the cautionary adage of Byrgenwerth - fear the old blood. I imagine repeating this prayer engraved upon it helps her cling to sanity for longer. Her beast form is huge because, like the clerics, as a member of the church she likely drank a lotta blood.

My headcanon for the Witches is that they're in Hemwick to collect eyes from all the Yharnam corpses sent there for mass burial/cremation. They're quite similar to the eye collectors in Yahar'gul, but I'm not sure whether that means they're affiliated with the School of Mensis, I rather think they're just "random" hags who take up residence on the outskirts of Yharnam to collect eyes for their own insight and witchcraft. They could have been torturing that locked-up hunter to learn how to use Caryll runes for further cosmic powers.

Shadows of Yharnam are the pthumeru guardians of the Queen Yharnam, yup.

Rom is... pretty obscure lore to me. She was once granted eyes, Micolash believes, by Kos. This makes me think that Willem used a part of the umbilical cord ripped from Kos' washed-up corpse to conduct a ritual that turned a Byrgenwerth student into the kin that is Rom (or an actual great one, I forgot if she's more than kin), similarly to how the player can consume great one umbilical cords to evolve at the end of the game. How/why is Rom hiding some rituals and/or preventing the Blood Moon's descent? How was the Grand Lake pocket dimension created? How is it all connected to the cut content "grand lake of mud" with the physical moon presence fight? Why is there a Rom-like corpse at the Altar of Despair? Why is there a Rom in the Chalice Dungeons? I have no idea. Maybe I'll ponder it some more.

Cleric beast just happened to be there. They're a cleric that turned into a beast (funny that) and most clerics were probably in the cathedral ward which is why it comes from there.

One reborn has a lot of theories around them, personally I go with it being a mensis attempt to create a great one by effectively throwing bodies together in the ritual until their minds merge

The big celestial emmisary is probably just the same as the others

Micolash thinks he's just going to forget everything, he doesn't realise he's already dead.

The baby (Mergo) is a great one, the wet nurse is making them her surrogate child in a way. Another theory is that the wet nurse is just something created by Mergo to try and protect themselves, since the 'nightmare slain' doesn't show up until Mergo themselves die.

Gehrman wants to set us free from being tied to the dream and the hunt, him killing us is him severing that connection. Simmilarly killing him is often viewed as an act of mercy, trying to set him free in our place. He's stuck in the hunter's dream to fulfill the moon prescences goals, and doesn't want us to share that fate.

Moon prescence is the most up to interpretation thing in the game, we know very little so i'd recommend looking at other theories to see what you think.

The achievements confirm we become a great one, but even if that wasn't the case it would be clear because the umbilical chords are from infant great ones and grant insight, their descriptions talk about how Willem wanted to use them to ascend. We aren't literally the moon prescence, we just look like them.

The doll will act as a surrogate mother for the hunter, there are some dubious theories that she is a great one herself but I think it's just meant as a thematic ending.

You forgot the Queen

Micolash is what really what happens when Gems fuse, he's actually getting off, there's a whole hidden arousal stat coded into the game.

My head Canon for the one reborn makes total sense to me but is probably easily proven wrong somehow idk. You know the idea of a monkeys paw? You wish for something, it grants the wish but usually in an unfortunate or unexpected way? It's like mensis were conducting a ritual to bring mergo back to life? perhaps they could hear the crying, well they wished and did all of their creepy ritual shit, and the moon presence or amygdala or whatever the heck, maybe even something else, answered their wish but in a harrowing and completely unexpected way, they birthed a child into a physical body, sure, but what the heck did they actually get.. well.. that thing.

I know someone else already answered but I've been desperate for a place to dump my theories and perspective on the lore.

1. The Cleric Beast is just that, a cleric that transformed due the massive amount of blood ministry it was exposed to. The church is the one employing the Hunters so I doubt they are using it as a guard dog, rather I suspect that it had escaped from Cathedral Ward just above and no one has come for it yet.

2. Father Gascoigne is stated to have been from a church in another land and outsiders who want to use the healing blood are forced to work a Hunters if they can't afford it, so he likely came to get help for himself or his family. When you fight him he has already gone blood drunk and is on the verge of beasthood. His daughter tells you that her mother had gone looking for him so it is certain that he had killed her himself. (I have some more regarding his family but that's all for him)

3. The Bloodstarved Beast was probably some member of the church due to it being larger than others in Old Yharnam. The reason it's blood starved isn't personal, rather it had been cut open and drained by the Hunters likely for the ritual blood that you get from the altar it's in front of. It is filled with poison because the residents of Old Yharnam had all been infected by a disease called ashen blood and had taken large amounts of healing blood to cure it, unfortunately turning them all into beasts.

4. Vicar Amelia is a high ranking, possibly the highest seeing as she shares a title with Laurence, hence why she turns into such an awful beast. I think the reason she turns when you enter is because you distract her from her prayers.

5. The Witches of Hemwick are witches that have a lot of and know how to make use of insight. The tools found in the village, the executioners, and the fact that they can be found in Yahar'gul implies that they were helping the School of Mensis and probably providing the limbs used in The One Reborn and other similar creatures around there. As for the corpse they were guarding, it was probably just a Hunter they captured and were going to cut up.

6. Shadows of Yharnam are the guardians of Queen Yharnam and do her bidding. They guard Byrgenwerth because that is where Rom is, and killing Rom will allow the blood moon to rise and Mensis to perform their ritual proper. Due to their station they've also contracted the strange snake plague that infests the deeper section of the forbidden woods and learned to make use of it, likely possible thanks to the fact Pthumarians are superhuman beings with some kind of innate magic.

7. Rom was a Scholar of Byrgenwerth worth, Wilhelm used the umbilical cord taken from Kos and her Orphan in order to ascend Rom into a Great One (Yes, I would say she is a proper Great One). Rom now has all the insight and knowledge that Byrgenwerth wanted but would share none of it because as her title, vacuous, implies she no longer has a mind as it ascended beyond her body. The lake that you find her in is her nightmare, a realm created by a Great One, hence why you just suddenly end up in endless shallow water.

8. Martyr Logarius was a member of the Healing Church who had the specific goal of exterminating the Vilebloods and while he mostly succeeded the Vileblood Queen was immortal. In order to ensure that no more Vilebloods were created, he made himself a martyr become a kind of litch using the power of the slaughtered Vilebloods. He now both prevents her escape and anyone else from finding her.

9. Darkbeast Paarl, darkbeasts are a kind of beast that produces blue electricity. While they look undead it is likely that is just their default appearance. While nothing specific is known about Paarl I agree that it is likely Archibald, or at least that it would be more interesting if it was. He is the only name given in relation to the darkbeasts and Paarl drops the Spark Hunter badge that is used to obtain all of the tools Archibald developed.

10. The One Reborn, while the Choir was trying to commune with Ebrietas the School of Mensis wanted to create their own Great One like Byrgenwerth did. They used the bagmen, Hemwick, and even their own Hunters to kidnap people and shove their parts together in some twisted ritual. This of course fails because they don't have what Byrgenwerth had, they needed an umbilical cord.

11. Celestial Emissary is the only successful attempt of the Choir's experiments. They used the blood of Ebrietas (The Old Blood is not the blood of Ebrietas) to try and create a great one and they succeeded or at least got as close as possible with the Emissary. It's job is to communicate with Ebrietas so the church could learn about it and the other Great Ones so that they may ascend humanity to the next level. The little blue guys are failed attempts and the Living Failures are closer but still not enough.

12. Ebrietas is a Great One that was left behind when all the others ascended or abandoned their physical forms or whatever they did. She was found in the depths of the Isz Chalice dungeon by the Healing Church. They notably found the Isz Chalice after Byrgenwerth and therefore after the Old Blood already existed. Ebrietas is kept deep in the upper ward where they study and attempt to communicate with her while she sits there depressed that her family left her.

13. Amygdala is a Great One found in the Nightmare Frontier which is its own nightmare realm. There are lesser Amygdala found in Yharnam that were likely summoned or drawn in by the School of Mensis since only one is found away from Yahar'gul and its entrance. I believe that they are Amygdala's children/creations similar to the spiders summoned by Rom. It's being worshiped by Patches, a former member of Mensis based on the fact that every other spider person is with them.

14. Micolash is the leader of Mensis, they had all sacrificed themselves to create a nightmare realm that would allow them to meet with Mergo and obtain its umbilical cord. However even though they had succeeded, the ritual caused "...the stillbirth of their brains" (I believe they became the Brain of Mensis). Except for Micolash who may or may not have been that crazy before he did the ritual.

15. Mergo's Wet nurse is a Great One that seems to have dedicated its life to protecting the infant Great One Mergo. The Wet Nurse seems to be lacking a physical form as the cloth it wears is covering nothing, meaning it has some sort of relation to Oedon the formless Great One (Mergo's father)

16/17. Gerhman is the first hunter to exist, with all others modeling themselves after him. He and Laurence had used an umbilical cord, possibly the same one used for Rom, to contact a Great One known as the Paleblood or the Moon Presence. Great Ones that lose their child yearn for a surrogate. In exchange for creating the Hunter's Dream, a nightmare realm, and therefore giving the hunters that access it immortality, Gerhman was to remain trapped there as its child. Gerhman offers you escape from the dream and therefore escape from your duties as a hunter but if you refuse he will force that escape on you because he doesn't want anyone else to suffer his curse. If you kill him the Moon Presence will descend to make you its new surrogate or if you have consumed 3 umbilical cords you have ascended beyond its power and slay it to become a new Great One yourself.

(A lot of this is my own conclusions drawn from in game text and other people's theories, so don't take my claims as fact. ) (Also I'm happy to expand on anything as needed)

You gotta spread these posts out. Too much for anyone to answer in one post wholly.

Rom I will say was a Byrgenwerth scholar turned great one. Not stopping the blood moon, but hiding the fact that its happening.

She ascended on insight alone, not blood, which made her vacuous, much like Mensis and the still birth of its brain, because it cant comprehend the Truth.

Id say shes kind of a cosmic filter, obscuring the true nature of what's going on in Yarnham. Most likely to protect the ritual from being interrupted by a great hunter like yourself.

She weaves a web of illusion and the lake is the "bulwark" thag obscures her. Once she is defeated, the veil is lifted and yarnham descends into hell and madness.

I love character, not so much the boss fight.

Cleric beast likely wasn't intentionally guarding the gate. He just happened to hop down the bridge, ambushing you like a predator.

Gascoigne went blood drunk like hunters before him, likely mistaking his wife for a beast via illusion.

BSB had its body literally flayed so it could get more blood. Look around, there's likely not much blood to go around down there. You're a good bet for food when you show up.

Amelia was always going to turn into a mad beast, we just happened to walk in when it did and we as quickly put her life to rest. That pendant was likely hers, the only remnant of her life as a human as her body is completely transformed, barely resembling a human now with her Wendigo look.

No idea on who the body down there was. It wasn't caryll most likely, but who's to actuallysay? You could headcanon them to be Caryll. And there's not much on the witches, other than they're collecting eyes. They could've been students of Byrgenwerth and followed in the belief of master willem that insight will be the way.

Spot on with the Shadows.

Rom is called a Kin, humans that ascended but aren't quite complete to be called great ones. Same with the emmisaries and Ebrietas. And it's more-so that she's casting an illusion. The blood moon is already up in the sky, indicated by the "A Paleblood Sky!" note in Yaharghul that is there before you even reach the woods. She holds back the truth and it's maddening.

Micholash was part of the school of Mensis, and they were attempting to commune with Mergo and/or create a great one. And using the bodies of the unseen village's townsfolk, they definitely made something. It's up to interpretation on who "The One" is. Likely, it's not an actual great one in there. Just the conglomerate of the townsfolk minds.

A lot of the Loran beasts posess lightning powers, I'd say it's not someone recent who was turned into it. Perhaps it's simply energy posessing the skeleton and not something that is truly alive.

He's not protecting her vileblood. He's protecting the secret of her immortality. The executioners were sent to eradicate the cainhurst nobles for their use in a different type of blood, something that the church deemed unholy. And annalise desires a child of blood to one day be her heir, so keeping her guarded means that will never happen and also no one will figure out her secret.

Amygdalae are simply great ones watching us. Our minds likely wouldn't comprehend the reason why they are here all around watching us. Perhaps they're simply keeping us in check, we don't know.

All the emmisaries are choir experiments, some turned out more successful than others I suppose like the boss version.

Ebrietas was kin for certain, so she was a human or pthumerian at one point. What her purpose to the church was, uncertain. My thought is that she was the original fountain of the church's blood, and after a while people simply died off and she was forgotten down in that crypt behind the cathedral. There's also a theory that the rom there where she prays is what she originally was. What we know as Rom was Ebrietas's pupa form. She had that look of a butterfly so I'd say there's a chance.

Micholash being alive in the dream but dead in the real world has to do with the dream logic. It follows Lovecraft's depiction of dreams, as they're realms very similar to ours but also alt dimensions that we go to in our dreams. In Bloodborne, the nightmares are basically purgatory, at least the hunter's one was. So he died in the real world and instead of moving on to the afterlife was put into the nightmare for an eternal life till we come along.

Yes, the Wet nurse was a great one who heard the calls of Mergo and came to hush it up. It feels like the whole hunt is just so the moon presence can also have some peace and quiet lmao.

Gehrman was trapped by the moon presence, likely he communed with it and made a pact to create the hunter's dream and keep the hunting going. Likely the Moon Presence is doing this for it's own goal of control. We "kill" Mergo to end our hunt, but being given mercy by Gehrman will just mean this keeps going. We take it into our own hands to kill him and put him to rest, as well to kill the great one for good and let Yharnam rest. We kill him without eating the cords to gain a great one's power, it just takes us in and puts us in his shoes to let the hunters go after the many long nights.

very sorry for very long comment to follow, keep in mind this is my interpretation and by no means final. also: i'm not talking about cut content, i believe it was cut for a reason, and FS published the game in the state that they wanted it to be in, even if there are artifacts from cut content: \ "Idola/Idona will be the judge!" and "This is the judgement of Luvan" are both probably meant to refer to figures, maybe great ones, representing Isz and Loran, but like i said there's no in game basis for it.

the Cleric Beast is, as the name would suggest, a cleric of the healing church turned into a beast. It stands so early on in Yharnam because you fight him on the Great Bridge, which is meant to lead to the Grand Cathedral, which is obviously where the clerics came from. Thematically, sure, he serves as a gatekeeper and an omen of what's to come, but ultimately he's just sort of there.

Father Gascoigne is a well trained man from a foreign land, possibly the same from which Eileen came, who has gained notoriety within the Healing Church and Hunter's Workshop. In his notoriety within the Church and his frequent exposure to the blood of beasts, he became blood-drunk, and underwent the horrific transformation we see in his boss fight. I don't believe his wife was killed by a beast, considering we find her in his arena, rather he was the one who killed her in his beastly fervor. When you use the music box, a reminder of his family and his humanity, he clutches his head and is stunned, unable to move or fight. Like Redgrave said in the Paleblood Hunt, how else could he react, remembering how he butchered his wife?

I never thought about the title of the blood-starved beast really, that's a very interesting take on it, especially with Djura's insistence on their humanity. Personally, I think that the beast is a cleric, being found in a Church and being one of the most horrific beasts we fight, (and as it was, clerics transformed into the most hideous beasts), but had it's transformation stunted by it's back being cleaved and peeled open, in an attempt to prevent the transformation from occuring at all. \ Brador's Bloodletter tells us that "[Bloodletting] is the only means of expelling tainted blood, or so Brador believed". Brador, being a Healing Church assassin, and a Hunter, operated in the quiet disposal of beasts, and perhaps the Blood Starved Beast is a product of his failure to prevent the transformation. \

Vicar Amelia is one who I have less of a theory and more of a headcanon on. I think that she is ultimately massively unqualified for the job, and was deliberately and maliciously put in charge by Laurence while he sought the Beast's Embrace, and evolution with courage. \ My reasoning is simply that women, in Bloodborne, are all sufferers. Not a single woman has a happy ending. A woman being exalted to such a place of power, by the previous male Vicar is strange, and a woman with absolutely no backstory, too. We know that Laurence began at Byrgenwerth, and then practically singlehandedly implemented the practice of blood ministration and established the Healing Church. Vicar Amelia, however, simply appears to fill that gap left by Laurence. \ I think that Laurence appointed a random member of the few who remained in the crumbling Healing Church as the scourge of the beast raged on, before he transformed himself, so that it may continue to hold some degree of control over Yharnam. This woman, no matter the degree of wretchedness she lived in before, was given a simple task. Accept the gift of blood. As long as there was someone in charge of the church, the rest of the few who remained loyal to it amidst the scourge may continue to do so. Amelia accepted the blood, and felt her humanity begin to slip away. At this point, there are coping mechanisms employed by Yharnamites, such as focusing on the very human concept of fashion (Threaded Cane, Top Hat, etc). Amelia chose to focus on her own identity and religion, and instead looked to her locket, containing the likeness of someone very dear to her, perhaps a partner or family member, and she also observantly chants the adages of the Church. The player, when entering her arena, breaks her concentration. The unwelcome beast overtakes her, hence the transformation

i will write more but i gotta go to my psych lecture 😭