The following is very much a WIP
A soul is a valuable thing, particularly that of a great mortal. There exist creatures in the realms of the dead who sustain and empower themselves by consuming these souls. These beings are known by multiple names, including; Collectors, Harvesters or Severants.
Severants are seemingly immortal, but not invincible, beings that reside in the realm of the dead. They are powerful and do not require the same amenities as mortal creatures, such as air or food. They do however, require sustenance. Unless severants feed upon the souls of fallen mortals, they will expire and fade into nothing. They can also be forcibly expired in battle with monsters, severants and even mortals. Some severants have been known to return from this expiration, or rather they been recreated by the belief, worship and fear they instill in mortals. Although, this is a lengthy, costly and painful process that every severant would avoid at all costs if possible.
The process of soul consumption is different for every severant, as is what they choose to do with the remnants. Some place the remainder is afterlives of their own creation. Some send the scraps back to the living world, to be reincarnated. And some simply devour the entire thing, leaving nothing behind.
Severants differ greatly in appearance and ability too, as much if not more than the creatures in the living world. These aid, or hinder, them in both the living and dead worlds and, when witnessed by mortals, will sometimes inspire tales and myths of gods, spirits and monsters.
Most severants are unsure of their origin or purpose beyond consuming souls. However, just like in the living world, the dead realm has multiple tribes and faiths that hold their own beliefs, theories and hierarchies.
The realm of the dead, sometimes known as The Other Side, overlaps the living world, occupying the same physical space. Most mortals cannot see the realm of the dead, though on rare occasions, mediums, oracles, dreamers and those facing near-death experiences may catch a glimpse of the other side. These glimpses help fuel the stories and myths of death gods, psychopomps and ghosts.
Unlike those native to the living world, severants can travel between the worlds, though their power is significantly limited within the living world.
Time is not necessarily synchronous, or even linear, between the worlds. Severants may battle for years over a recently dead soul before their body even hits the floor in the living world. Alternatively, centuries may pass for the living where only minutes do for the dead. Such discrepancies rarely bother the Severants as aging is no concern and time always seems to flow in convenient manner, most of the time.
Severants aren't the only residents of the dead realm. There are unknown numbers of monsters that seem to defy classification. Some have theorized that these monsters are simply a different, more primal breed of severant, as they too are drawn to souls, or they are some manifestation of the souls that were never claimed. Regardless, they are fearsome creatures that one must always be aware of.
The value of a soul, and the power it grants those who consume it, it's not reflective of a creature's worthiness or morality. Rather it depends upon the influence that creature had and their possession of particular attributes, such as remarkable courage, cunning or creativity. A simple mouse, an infant or an especially mediocre person might suffice for light brunch but a generation defining warrior, leader or artist is veritable banquet of delights. However, even the humble yet courageous peasant standing up to oppression and abuse may be among the most fulfilling meals.
Some severants are very particular about the souls they consume. They may exclusively partake in those of particular professions, faiths, classes, species or moralities. Most cannot afford the luxury of being so picky.
You will be playing as a modest party of severants, creatures who consume souls for sustenance and power. You are strongly encouraged to choose one or more examples from real-world religions, mythologies and folklore as your main inspiration. You may not be as powerful as the characters are normally perceived to be (i.e. you are not omnipotent gods), but your appearance, personality and abilities could be similar. One way you could think of it is that stories about you are the inspiration for these figures in public knowledge.
Examples of figures to take inspiration from:
Regardless of the source material, the characters are not omnipotent or omniscient beings, they are not invincible or unending, they can expire or be forcibly expired. I.E. We will still play by the normal rules of whatever system is in use, hit points and death still work the same way, but may not represent the same things in a roleplaying sense.
You may use the following, modify them, or make your own. You may even have multiple players playing variations of the same source (e.g. two different versions of Hel).
Grim is a skeletal figure in a long black robe. They wield a scythe both as tool and a weapon. They are generally quiet and brooding.
Example DnD5e build: Phantom Rogue or any death/necromancy themed caster
Muut is an owl.
Example DnD5e build: Aarakocra/Owlin Druid or Ranger
Horn (or The Horned One) is a bestial being with a fondness for animals. He struggles to see humanoids differently to other animals in the ways many others might.
Example DnD5e build: Minotaur/Satyr Druid, Ranger or Beast Barbarian
Azrael carries a scroll with a list of names. A person's name is added at birth and crossed out at death.
Example DnD5e build: Divine Soul Sorcerer or Scribe Wizard
Thanatos has black wings and wields heavy chains as weapons to imprison reluctant souls. He may not be as strong or as wise as some other deities and spirits, but he possesses indomitable will and cannot be persuaded or coerced.
Example DnD5e build: Aasimar, Grave Cleric or any mostly non-martial anti-necromancy build (Probably with homebrew/flavoured chain weapon/spell)
Morrigan is a queen of war and death. She encourages people to fight through prophecies and whispers. She can also turn herself into a crow.
Example DnD5e build: Elf or Human, Circle of the Moon Druid or Swarmkeeper Ranger
Valkryie is a proud and fierce warrior. She flies with gilded wings and fights with a spear.
Example DnD5e build: Aasimar, Barbarian/Fighter
Samedi is a foul-mouthed, hedonistic man with a fondness for tophats, tailcoats and skull shaped masks/facepaint. He commands the Gede, lesser beings who are similar to Samedi in many ways, though not as strong.
Example DnD5e build: College of Spirits Bard with Noble (Retainers) background
Creating your own characters, not inspired by IRL myth, is allowed, but I will ask that you also create the mythology surrounding them (or choose a suitable suitable character from another work of fiction). Below are some examples using characters from my other settings.
Skjalver is a pale Nordic looking woman with black eyes. She carries a longshorman's hook which she uses to pull souls from their bodies. She then places each soul in one of two jars.
Example DnD5e build: Aasimar Death Cleric
Sepulcrus is a black hare that is often found silently observes fights and battles, deciding the victor, and later consuming the loser. It is unclear exactly how much influence, if any, Sepulcrus actually has over the battle he witnesses, he may just be a good predictor.
Example DnD5e build: Haregon (some control/support build that helps others win fights without being too obvious)
The game will likely begin with the party cooperating to acquire souls. Some of you may collaborating with this group for the first time, others may be long time allies. You are likely in the midst of fighting rivals, or other monsters that haunt the dead realms. Should you succeed, it will be a modest haul of minor souls, it won't be long before you need more. This has been your status quo, for some time. But that may be about to change. There are rumours that the greatest hero of several generations is about to fall. The race is on.