Player Secrets

Every player will be asked "Tell me about a typical day for your character? What is their job and what do they do there?  What is their routine?  What do they enjoy doing in their free time?"

Any details needed that are inconsequential to the plots can be invented by the player, if any divine communion is performed, they can learn the truth at the DM's discretion. Hints should be given and found regularly as to their true natures/reasons for living.

The murderer
The player wakes up in a lavishly decorated home, standing over the body of an important noble, with his blood on the PCs hands and arms, and spattered on their face and clothes. They have no memory of how they got there or of any altercation, nor can they find any bloodied weapons, just their own bloody hand prints on the corpse and the floor. The body has been stabbed multiple times with a piercing weapon, larger than an arrow but as narrow as a short-sword or dagger.

Mysteriously, the entire house is empty and escaping is easy, though the player has to make a CON save (no DC, save is automatic) 4d10 minutes later. Shortly after this, the player finds out that the noble is still alive and well, and carrying out their business as usual, though the player has an impending sense of doom about pursuing this noble directly, and indeed the noble will attempt to escape the player at all costs, and will send assassins after the player to eliminate them.
 * The player was drugged with an amnesiac, making them forget being led into the room and tried to save the dying man's life. The man was assassinated by a doppleganger and the player was framed in case things went wrong.  The player was supposed to have been killed within 1d4 hours of being poisoned, but the CON save was made to not die.  The doppleganger assumed the noble's life after having been their butler for years, and if they know the player is alive, they will disappear and attempt to assassinate them to eliminate them as a potential threat.

The monster
The player awakens from a stupor submerged in liquid, completely numb and unable to breathe or move or feel or see anything. After a few minutes, the player begins to feel their face (unable to breathe or open mouth or eyes at all), then their arms. (If the player uses their arms to feel around, they will feel no torso or legs until a few minutes later) They will feel small things swimming in the liquid with them, like tiny crustaceans, squishy snakes, or spherical fish. The feeling in their legs will come next, and they will feel solid ground not far beneath them if they stretch. (the liquid is thick and viscous and they will have difficulty staying grounded.) Finally they will begin feeling in their torso and will begin to float to the surface. As they swim around, they will feel other larger bodies in the liquid with them.

When they break the surface they will have difficulty seeing (darkness), hearing (silence) and will still not be able to breathe (breathlessness). The liquid will appear as an ever-shifting flesh-colored pool with indeterminate shapes and colors mixed within. They can find an edge and climb out of the pool, and after 1d4+1 minutes, will begin coughing and retching up liquid for another 1d4+1 minutes. They will find a door if they try, and the door will lock behind them once closed (strong iron door, no handles, no way to open).

In this next room are all of their belongings they carried with them the previous day, and another door that leads outside. After 4d10 minutes, their vision will become less blurry and will sharpen back into focus, the room is worked stone on all sides, and there is one wall sconce and one candle on the a plain wooden table (no chair) along with any of their metallic belongings, including buckles and buttons, weapons, and metal parts of their armor. The rest of their belongings will be in a chest on the ground next to the table, their armor will be covered in small amounts of blood. 4d10 minutes longer, their hearing will kick back in, and if they are still in the room and listen closely, they will hear quiet confused nonsensical gibberish that sounds like common speak, coming from behind the door they came through.

Once they leave, the door shuts behind them and locks, and once the door is out of sight, it ceases to exist.
 * The player was 'reincarnated' by a gibbering mouther pit, formed from their ever-changing shapes and fleshy pieces into a perfect replica of their body. They were not to become conscious until a ritual was performed, but they somehow woke up early and exited through a special portal that leads any person who passes through to a place most familiar to them.  If ever discovered as an abomination, they will be pursued by cultists and gibbering mouthers whose intentions are to capture or kill if need be.

The mystery
The player will have their entire life erased, everyone they knew and everyone they grew up with, including any family, will deny their existence in full and under any truth spell imaginable. The only people who recognize the person are any children and any animals they may have been close to prior to today. If they consult with any Gods, they will in fact acknowledge their entire life, but will not know the specifics of why their friends and family have forgotten about them entirely.

Any possessions or legal documents proving their name, station, or property will now belong to a name that is an anagram of their own name, and that person will be known by others, but they will not know anything very specific, the same gender, and race of the player (half-elves could be mistaken as elves or humans as well), and they will recall them only as boringly normal, forgettable, and unremarkable.
 * The player was the subject of a powerful spell being tested by a secret group of mages, and needed someone of their exact situation to make sure the spell works properly, they will spy on the player in their attempts to be remembered, and once its solidly confirmed that they are forgotten by anyone of consequence, they will lose interest and abandon the player to their new life. If the player discovers their involvement while the mages are monitoring them, they will try to kill the player using indirect magic.  If the player discovers their involvement without them knowing, they will remain unaware until the player finds them and makes themselves known in any way

The survivor
The player will find themselves in an inescapable situation against insurmountable foes. The player will suffer the total dismemberment of their bodies, and will feel and see everything, eventually passing out from shock. They will awaken the next day, laying on a blood-stained patch of ground with their armor in pieces and their belongings scattered nearby. They will find scars in every location where they remember themselves being cut, but otherwise will not find any physical harm having come to them, any companions they were with will be killed as they were, but will be found dismembered.

There will be stories of this evil that killed many, but the player will be the only known (or unknown) survivor. If the player has any previous memories of close brushes with death, they will remember waking up in this same fashion, with other scars if applicable.
 * The player is actually a reincarnated hero, having been granted immortality by an unknown deity, they age normally and when they die in their old age, they are reborn without their previous memories. There is some knowledge that bleeds through, but never about their true nature.  Any death suffered will have them wake up the following day after being fully healed no matter the damage or distances involved.  If disintegrated, or killed in any way that would normally prevent resurrection, the player 'dies' and is reborn elsewhere as the cycle continues.