#but not wrong

On The Old Blood / Beast Scourge Origins

It is unknown for sure whether the misuse (or excessive use) of the Old Blood triggered the beast scourge- or if the events of the fishing hamlet cursed the blood and tainted it. Lore seems to point to the excessive use and excessive imbibing of the Old Blood as the catalyst for it becoming Tainted. I have three different theories as to what caused the Tainted Blood:

A: Aligning with lore- The fanatical and excessive use and fervor surrounding the Old Blood did cause the Beast Scourge. The reason being is it's excessive use: Laurence touted this miracle cure for any and everything- from the common cold to deadly disease, The Old Blood can cure all! However, I believe the blood had a viral component or mutagen- I mean, Eldritch God Blood, come'on. Definitely something nasty in there that isn't made for human consumption.

 I think the excessive use caused the virus/mutagen to build up in the human body before it causes a rapid evolution of the human dna and genome. Either because we as humans do not have the necessary anti-bodies against said virus/mutagen or- well, again. Eldritch god blood isn't compatible with regular ol’ humans. I also feel like if The Old Blood had been diluted, or less of it was used in treatment (instead of a huge blood transfusion, maybe a tiny vaccine shot?) It probably wouldn't have gotten so far out of hand so quickly. 

Another thing that supports this theory, is there are very few female beasts- Vicar Amelia being one, who excessively imbibed in the blood, and another female in the forbidden woods (if I recall.), which lore attributes to, women menstruating. Women replace the blood in their bodies through menstruation, which would lower the amount of the virus/mutagen in their bodies.

B: Fanatical devotion often twists and malforms that which is worshiped. This is still semi-aligned with the lores theory that excessive use caused the scourge- but focuses more on excessive devotion. We see it in several characters: Vicar Laurence, Vicar Amelia, Master Willem…All, in some way, show the same fanatical devotion to the point it literally consumes them (Turning them into beasts, or holding them hostage, as with Rom and Willem). 

I think, the Great Ones possibly used the surge of worship and devotion to influence the mind of the humans that consumed the old blood. As it would give them a direct conduit of influence over the body. (As in the later parts of the game…come to find out the Great Ones really just want to have babies, so it makes sense to me they would influence the humans to move toward that goal- even if it inflicts madness or great chaos and strife. I digress). 

Ultimately, as stated before, fanatical devotion can often twist and malform what humans construe as divinity, particularly when greed is added into the mix. Laurence being the prime example- he had great intentions when he brought the Old Blood to Yharnam. Did miraculous things with it, even. But somewhere along the line, someone got greedy or power-hungry. 

I haven't analyzed Laurence as a character so don't come for me when I say this: but part of me really does believe the beast scourge is entirely the fault of Master Willem and Vicar Laurence because they got into a ‘who's answer is the most correct’ pissing contest. In Laurence's case, I think he fell into hubris.

 I think he was so convinced that the Old Blood was such a sign of divinity that he became utterly enraptured and consumed by it, and he was driven by an all encompassing need to prove it- in part to try and change Master Willem's mind that, yes this was the path for humanity to take, just wait and see- and in part because, well. Quite frankly I believe he was driven to madness by the influence and whispering of the Old Ones because of how much Old Blood he imbibed, and consumed- he disregarded his Masters Warning and fell prey to eldritch machinations.

C: While still semi-lore complaint, it's a toss up, really. This theory is pretty much: the slaughter of the fishing hamlet and lust for power, and the resulting curse for their crimes is ultimately responsible for the scourge, and the Old Blood becoming tainted. One of the main things that works against this is that the scourge started to take place before the events of the Fishing Hamlet, so I still suspect either a virus/mutation caused by overuse of The Old Blood- but one that rapidly expanded, and was exacerbated by the events of the Fishing Hamlet which caused the blood to become ‘tainted’ or ‘cursed’ in retaliation of the Old Ones anger. This is kind of supported by the facts that, very obviously the Beast Scourge rapidly got out of hand and became overwhelming after those events, where as before it seemed to be mostly containable. 

I theorize that, if the events of the Fishing Hamlet had not occurred, the worst that probably would have happened is the Ashen Blood scourge, and maybe people mutating into beasts every now and then, instead of a whole ass outbreak of the magnitude it got to. All in all, I think both events together (The overuse of the Old Blood + Events at the Fishing Hamlet) are what ultimately triggered the tainting of The Old Blood and rise of the beast scourge.

GH- Blood Ministration, consumption of The Old Blood, or repeated exposure to it alters the DNA. There is also a vast distinction between the effects of the Old Blood, and the Tainted Old Blood.

While it's pretty self explanatory, this is a very firm headcannon about Bloodborne to me. It's supported by cannon in that it obviously alters something in the human body, thus causing the beast scourge and transformations into beasts. So it stands to reason it alters or mutates the dna in some form or fashion, and the more you consume or are exposed to it, the more your body becomes altered until you succumb to the transformation.

I personally theorize it acts more like a viral mutation, and there are ways to lower the viral load as it builds up in your system (The Bloodletter weapon was specifically made for this) and some cannon sources also support a similar theory (such as, why there are few to no female beast transformations).

Hunters are, obviously at the highest risk for changes, as they undergo blood ministration, and also regularly consume blood to regenerate health or strengthen weapons. This is even more apparent after The Healing Churches bloodstock becomes tainted or cursed- more and more hunters fall to the scourge, which is a contributing factor to the overall problem as the game progresses.

My AU-Lore takes this a bit further, in that any human who undergoes blood transfusion is no longer considered ‘Human’- but rather an ‘Augmented Human’- as we can see, both in world, and in lore, those who have become Hunters have somehow ‘transcended the bases of humanity’. Whether that manifests as increased reflexes, strength, abilities gained as you play through- the point stands- at some point you are no longer just a ‘simple human’.

While my AU does mostly coincide with cannon lore, I do take some liberties with mechanics, and established lore, as well as creative ways to spin the lore to fit my narrative.

Hunters and The Old Blood: As stated above, Hunters are no longer considered ‘human’ once they start imbibing or undergo Blood Ministration. The longer a Hunter Imbibes, or is exposed to the beast scourge blood, the more drastic the changes in the Hunters become. It also depends on the hunters psychological state, as well as their overall physical health on how far they descend into beasthood.

Hunters that undergo ritual cleansing transfusions or inscribe certain Runes into their person have a higher chance of resisting this decent into madness or falling prey to the changes of beasthood. Some changes will still occur despite this- even with ritual cleansing: The paling or darkening of the hair and nailbeds, fangs or canines growing out, changes in the shape or color of the eyes, changes in senses such as smell or taste. Changes in body odor, increased reflexes, reactions, speed, or strength.

While these things are good starting indicators that someone may be descending into beasthood and should be closely monitored- they are also naturally occurring changes caused by consuming The Old Blood, as in my HC, it alters your DNA and causes these changes over time. Some of these changes are also probably caused as a result of the blood ministration alone (Strength, reflexes, taste, sense of smell, speed), and are permanent changes to the overall DNA of the Hunter.

Those who were given the untainted Old Blood only seem to have descended into beasthood completely if they continued to imbibe (drinking bloodwine, multiple transfusions, completely forgoing cleansing rituals) or were mentally unstable and allowing the Old Ones to overcome them (Descending into madness, fanatic devotion, excess greed, broken minds, excessive trauma or traumatic experiences (which lets be honest, the whole game is just one big traumatic experience.))

Those who were later given the Tainted / Cursed Blood however, seem to descend into beasthood much faster than the Older Hunters. Tainted Blood Hunters also seem to display different characteristics and should always be monitored carefully, as cleansing rituals must be performed much more often.

Tainted Blood characteristics include: accelerated mental degradation, or bouts of aggression. Lengthening of the nails as well as darkening of the nailbeds, Lengthening of the canines and darkening of the scalarea. Extreme paling or darkening of the hair…..

Characteristics of those descending into beasthood that should be given caution and closely monitored: excessive agitation, aggression, or bouts of confusion. Small patches of hair growing out of the skin, excessive thirst or hunger, particularly for Blood Wines. Foggy memory, excessive talking to themselves or to people that aren't there. Misidentification of fellow hunters or places. Labored breathing, or intense insomnia. Restlessness….

Characteristics of those in advanced stages of beasthood descent: These individuals are dangerous, and should be approached at the Hunters own peril: Clumps of hair falling out or excessive hair growth over the body, maleformed or bulging/ mutated limbs or extremities. Complete delirium or confusion, talking completely to themselves, complete lack of awareness of surroundings, hyperfixation on one task. Extreme acts of aggression or violence. Strong or overpowering bestial or bloody odor. Complete discolored scalars, excessive drooling or salivation. Obsessive consumption of raw meat….

Cleansing Rituals: Bloodletting or a blood transfusion with a source of clean human blood (or blood that has not been exposed to The Old Blood) has proven effective at diluting the viral/mutated load that tends to build up over time in a hunters body. Likewise, imbibing in Ritual Wine (A human-blood based wine loaded with cleansing herbs, or wine that is infused with the blood of a Saint) while bloodletting also seems to delay the descent into beasthood.