[ ] You made an offering of enkephalin...... despite the being sitting on the throne taking the guise of an androgynous human you can tell that on a fundamental level it wasn't human at all. They made smiled at you like you were something exciting.
Anansi, an African Spider God of Trickery and Stories, often using puzzles and pranks to teach wisdom and knowledge to others. He is most notable being a Creator God who formed the Sun, the Moon and the Stars, earning all the stories that ever exist from the gods and granting them to the world, gathering all the wisdom of the world in a pot(or maybe a gourd) but ultimately releasing them for everyone else to have, and taught writing, agriculture and hunting so humans can take care of themselves in the wilderness. Also he stole food from Death which pissed him off and that is why people die, held disease in a gourd that he released into the world, is mortal enemies with cockroaches, and held a mock funeral for a gun so he could shoot the attendees.
As a Servant, probably either a Caster or Assassin that focuses on debuffing and manipulating his enemies while granting buffs to allies. Something like Subversive Activities and Shapeshifting are expected, possibly Clairvoyance from his Noble Phantasm. His greatest feats involve giving something of his to the human race, so a Noble Phantasm that improves others and might be permanently transferable
[ ] You offered the typical employment form that your agents sign, rewrote part of it to account for what the servant is being called into, why, and what their likely duties will be......... and an old Silver haired fellow came into existence on the throne reading it over with a curious look, before giving you a smile of white and red teeth.
Alexandre Dumas, Caster-class Servant, author of famous books such as The Count of Monte Cristo and The Three Musketeers. A support-type Servant whose kit revolves around making equipment and buffing others. He can create forgeries that are on the level of Noble Phantasms, increasing the ranks of items to the point they can surpass the original, along with rewriting the "Identity" of a person by inscribing new experiences and skills, essentially making a knockoff of Limbus Company's Identity System. He also has an intelligence-gathering skill based on "the passing and spirit of the era" and is really good with food. He literally has a Skill called Gourmand.
[ ] You made an offering of solemn laments essence, you can not give it away but you can share it........ the inhuman being reminds you of a mix of Funeral of the Dead Butterflies and Fairy based Abnormalities. Death clings to this being as it sits there on the throne with unreadable mannerisms like an insect.
Pretender-class Vortigern. Don't know if Oberon still is fused with him, or if this is even the Lostbelt version. How would that even work?
The Living Avatar of the Will of Britain, The White Dragon, The Insect of the Abyss, living doomsday device.
Fights by summoning and controlling insects, both large and small. Has Fairy Eyes that can see any lie, has high Item Construction, high Riding, knows enough about magic to teach and can manipulate memories, feeds off of Excalibur's light but also weak to it's wounds, can disguise Class, attacks and physical form including shrinking, can exist anywhere the concept of a "hole" exists. Skills grant incredible temporary buffs with large drawbacks, making them highly situational and timing paramount. Arguably his greatest strength is his mind, creating plots and manipulating factors that can destroy a nation.
[ ] You offered the fears and wishes of the facility, written as notes, recordings, photos of graffiti, all of them getting a simple message across....... 'I don't want to die here', you even found one of yours from a failed loop...... it was an unpleasant one you wish you didn't remember. The woman on the throne exuded a soothing prescence and the weight you had on your shoulders...... the weight you forgot was there, lifted. She was from the desert and offered stories to comfort you all for many nights.
Scheherazade. The Storyteller of 1001 Nights. Her Skills revolve around ensuring her own survival, such as creating an area where she has the lowest probability of death in the world to a Counter-King skill that allows her to understand pretty much everything about them. Her Noble Phantasm is the stories associated with the 1001 Nights. All of them. Yeah, it's a lot. She can summon anything contained within her collection of stories, and she can add to that collection new stories as she encounters them.