There are some connections which are unexplained:
1. The Blade of Mercy and Burial Blade are both said to be forged of siderite and are in fact the only 2 weapons we come across in Bloodborne that are forged of siderite. Mergo's Wet Nurse has 8 arms, but only 6 blades. It is curiously missing 2 blades. This is also interesting because the Burial Blade and Blade of Mercy actually do resemble each other and they resemble the blades that the Wet Nurse uses.
2. The Hunters of Hunters wear crowfeather garb. This garb strongly resembles the Wet Nurse, as if it has been based on the Wet Nurse's appearance.
3. The mineral siderite is said to have fallen from the heavens. The Great Ones are considered gods and some occupy the cosmos above us. This mineral could be said to come from there because it came from a Great One. When we approach Mergo (the baby) the Wet Nurse enters the arena from somewhere above, descending as if from the heavens.
These connections may just be thematic or there may be a deeper significance to them.
Blade of Mercy
A special trick weapon passed down among hunters of hunters.
One of the oldest weapons of the workshop.
Splits into two when activated.
The weapon's warped blades are forged with siderite, a rare mineral of the heavens.
Most effective swift attacks, such as after a quick-stepping.
Crow Hunter Badge
Badge of a hunter of hunters, who hunts those who have
become addled with blood.
The badge of the hunter of hunters is quietly passed down
from generation to generation, usually to an outsider from
To be entrusted with this cursed badge, one must be strong,
resilient to the seduction of blood, and gracious when taking
a comrade's life.
A Caryll Rune that transcribes inhuman sounds.
This red-smudged rune means "Hunter," and has been adopted
by those who have taken the Hunter of Hunters oath.
These watchmen admonish those who have become addled with blood.
Be they men or beasts, anyone who has threatened the pledgers of
the "Hunter" oath surely has an issue with blood.
Wood-carved mask of Eileen the Crow, hunter of hunters.
The beak contains incense to mask scents of blood and
Hunters of hunters dress as crows to suggest sky burial.
The first hunter of hunters came from a foreign land, and
gave the dead a virtuous native funeral ritual, rather than
impose a blasphemous Yharnam burial service upon them,
with the hope that former compatriots might be returned to
the skies, and find rest in a hunter's dream.
Eileen, the Crow dialogue: Central Yharnam Dry Docks / Cathedral Ward outside of Oedon Chapel:
"Oh, a Hunter are ye? And an outsider? What a mess you've been caught up in. And tonight of all nights.
Here, to welcome the new Hunter. Prepare yourself for the worst. There are no humans left.
They're all flesh-hungry beasts, now."
"Still lingering about?
What's wrong? A hunter, unnerved by a few beasts?
No matter. Without fear in our hearts, we're little different from the beasts themselves."
"What are you still doing here?
Enough trembling in your boots.
A hunter must hunt."
Cathedral Ward outside of Oedon Chapel:
“Oh, hello there. Perfect timing.
I must warn you not to go near the tomb below Oedon Chapel in the Cathedral ward.
Henrik, an old hunter, has gone mad. And he’s my mark…”
“Don't go near the tomb below Oedon Chapel in the Cathedral Ward.
I have business there first… ”
Tomb of Oedon after defeating Henryk:
"That wasn't necessary of ya.
But you have my thanks.
We made it with our lives… You're not bad at all.
You must have killed Gascoigne as well then.
He was falling apart… I'm sure it had to be done.
But try to keep your hands clean… The Hunter should hunt Beasts.
Leave the hunting of Hunters, to me."
In front of Grand Cathedral:
"Oh, is that you again?
I'm afraid I've made a bit of a blunder. I'm just going to have a short rest.
Oh, don't worry, I've taken blood. Enough to save an old woman.
No more dreams for me. This is my last chance.
What a fool I am. I'll have to tread carefully.
But that thing still lies in wait. Turn back. This is my score to settle.
My prey lies in wait this way. Turn back. This is my score to settle."
After defeating the Bloody Crow of Cainhurst:
"Don't you ever listen to your elders? No matter, you did save my life.
I don't seem to be apt for this life anymore… My glory days were long ago now…
Hmm, I know… Here, for you.
This too is hunters' work, but bears no honor. A burden you may choose to carry.
The decision is yours alone. Ahh, my eyes grow heavy…
Let me rest a while… …I'll be fine, just wait…"
"Look at you, you sorry drunk.
I’ll string you up like the filthy beast you are.
You shall not abscond your crimes!"
Severely injuring Eileen:
"Were you not once a hunter?
Is this sincerely what you want?
That’s enough now..
No one will blame you."
Being killed by Eileen
"You still have dreams?
Tell the little doll I said hello."
Upon her death
"You can’t go on like this…"
Hostile Eileen inside Grand Cathedral
"Heh heh… Few hunters can resist the intoxication of the hunt.
Look at you, just the same as all the rest…
The hunters must die…
The nightmare must end..
Only I can stop this madness! heh heh heh"
"The hunt makes hunters mad! Heh heh hah 'ah hah!"
When Eileen is severely hurt:
"The beasts cannot be stopped!
What good are hunters now?
Your blood is mine!
A hunter’s blood for me!
Your punishment is death! Death to the hunters!
Enough of this terrible dream! Hah hah hah!"
Upon her death:
"…Ah.. you monsters… All hunters must die! Heh heh heh!"