This story finds its beginnings during NG+6 after the defeat of Micolash, but come fully into effect by the end of NG+7. The character referred to as "The Hunter" is the playable character in the series. I thought it would benefit the story to have a third person account, so bear with me. All endings of the game are assumed to be verses the Moon Presence. Also please note that calling things Powerful One and Great One are different (basically it's a boss vs. a Great One).
"A hunter is a hunter, even in a dream."
But what did this mean?
Usually when an unusually powerful beast says something profound there is a meaning behind it. The Hunter found this long ago, while they were reflecting on the screams that echoed through their head. It was normal for them to have words or phrases from people they had never even met before filtering through, but to become bothered by a man that they heard in what they knew was a dream? That was new for them. They were sure of it.
They returned to hunter's dream with a strange feeling that there would be another Powerful One soon. They must become stronger before they could even try to attempt. How they knew this, too, they never understood. It was as though, without entering into a place, they knew what it held. Perhaps it was the effect of the strange "insight" that many referred to, which would explain the crying heard almost everywhere throughout the Nightmare of Mensis. Whatever the hell that was.
The Hunter never became used to the feeling of being transported from lamps to the Hunter's Dream, but they were always put at ease again by seeing what was likely their only friend on this plane of existence; the Plain Doll. She was always there to help make them stronger, or even just to talk. It was always nice to have someone that you know would never attack you.
"May I ask you something?" The Hunter said after channeling the echoes necessary through the Doll.
"Of course, dear Hunter."
"Where is reality?"
The Doll chuckled lightly and gave a sad smile and, for the first time in The Hunter's memory, simply walked away. The Hunter was flabbergasted - she had always responded to questions without hesitations and gave her best answer. Why was this any different? It was perfectly valid! They followed after the Doll throughout the paths of Hunter's Dream, before the Doll quickly darted into the area of the great tree and sealed the door.
"Wait! Do you know something I don't? What the hell is going on? What plane of existence-" The Hunter was stopped short by Gehrman's cane to the back.
"Some secrets are best left alone." Gehrman said - a sentence which resonated almost exactly with another's words from memory. The Hunter stared at Gehrman, confused as to how he could be so close to words that had never been uttered. "Return to Yharnam. Finish your job."
And so, like a soldier in battle, they did.
Returning to the Nightmare of Mensis was strange. The Hunter knew that there was a Great One just bordering their horizon, and yet, they couldn't place where. They searched, nearly getting lost themself in the strange nightmare, until they came to the source of the power. This power came from an unseen source nearby the crib in which a baby was crying. The Hunter knew instinctively that it was time for the final battle in their dream of reality. Good. The nightmare of their life needed to end. They wanted to return home with the contract fulfilled and a bill of clean health. Somehow, they knew this would never be the case. Perhaps it was the insight.
The defeat of Mergo's wet nurse changed something within the Hunter. They knew they had killed a Great One, and that it was their job to take its place - just not now. There was still another dream left to destroy to end the cycle and completely ascend. The Hunter accepted the fact that they could never again return to their old life now, and that it was their job to protect the fledgling Great Ones - themself included.
However, they had already failed at their job. The murder of the Amygdala, Ebrietas, Rom, the Wet Nurse, the Orphan of Kos, and the mercy killing of the Brain of Mensis had turned the Hunter into the culling power within the ranks of the Great Ones. Now that all the weaker links were destroyed, it would be time for a new, more powerful Great One to rise and continue the everlasting war within the ranks of the Great Ones.
The Hunter just needed to grow stronger.
Returning to the Dream, they were met with another surprise: Gehrman and the Doll were nowhere to be found. They searched all accessible corners of the Dream before attempting the yard of the great tree. There, they found not only Gehrman, but the Doll as well. This was a new development. Something that the Hunter felt as though should never happen, and yet, it did.
"Good Hunter. You have done all you can. Please. Return home." the Doll said - almost commanded - as she gestured to the Hunter to come forward. "Don't make this harder than it needs to be. You are in safe hands, now."
The Hunter knew something was wrong. Very, terribly, wrong.
"Your contract has been fufilled. Allow me to return you to your world. The sun is about to rise - let's make sure you're there to see it." Gehrman said with a calculating stare. The Hunter knew that he, too, felt the same wrongness in the presence of the Dream. It was the same kind of power that they felt in the Nightmare of Mensis. There was a Great One here.
"I will not." said the Hunter, preparing their weapon and nervously scanning the field before them. Was it another invisible one? Was it hiding? What was happening?
Gehrman sighed miserably - as though he was going through the same pain for the thousandth time. Shaking his head, he growled through exasperated laughter, "You never learn. You never think. Consider the Dream. Please. For once accept my mercy."
The Doll piped in, "I have always advised you to not think too much on the exclaims of your enemies, but Hunter this is different. Accept Gehrman's offer. It is time for you to leave the Dream and continue on in your life." On this note, she left. All was still. Calm.
Shaking their head, the Hunter began the fight. Gehrman wanted to win - he needed to win. But the Hunter was too powerful, and with every attack it was evident. Both hunters were still wary of the imminent presence of a Great One, and yet were fully aware that it was not from the presence of the Hunter. This strange new addition to the battle added an increased sense of desperation and ultimately fear. Both hunters could be cursed further, or smote, or had some terror done to them by this new party's addition.
When the Hunter was just seconds away from ending Gehrman's life, he asked one small favor.
"Do not fight your next enemy. It will be more powerful than -"
The Hunter had no time for Gehrman's pleas. They ended his life swiftly. It was as though the disintegration of his body left another voice inside of the Hunter's mind, another new declaration by an enemy: "I have failed you."
The descending Moon Presence gave no time for the Hunter to consider Gehrman's words. This battle finally sunk the Hunter back into the feeling of familiarity. They knew the attack patterns and weaknesses, and before long the Great One was defeated. The final step toward becoming a Great One had been completed, and as they acquired their new form it felt like changing back into their favourite garb. This was where they meant to be.
The Plain Doll picked up the small Great One. Although it was only a child, it was still one of the most powerful beasts to grace this plane of existence. "Someday, little one, you may even rival myself."
From deep within the great tree came a bloodcurdling scream of a man in pain. The Doll remained unfazed as Gehrman was reconstituted from his ashes. The pain of returning to the Dream was expected, but never accepted. He never came back by himself. He was torn from what was supposed to be perpetual peace. As his unconscious form slumped to the ground, the Doll hid away the young eel-like creature and returned with Gehrman's wheelchair.
"And so, the Hunt begins again Gehrman. This time, we will return to our usual run." the Doll whispered to the slave of the Dream. Gehrman whimpered in his stasis, as though he had heard her but didn't want to comply. "They knew too much and yet understood too little. They are not yet worthy."
She returned Gehrman's unconscious form to the workshop and assumed her form of a simple doll, inanimate and expressionless, as the Hunter came in. Gehrman snapped to consciousness, "Ah-hah, you must be the new hunter. Welcome to the Hunter's Dream..."
And so the cycle began again.
guess who's been obsessing over bloodborne for a long time hint: it's me it's definitely me someone help