In the far future, immortality is in the form of mind uploads and cloned bodies. But the soul is a real thing, and the old gods have returned to reclaim what is theirs.
Type: Blossom
Joining with the World Tree has put an even greater strain on the metaphysical barriers. Some of the weaker essences see it as a means to escape their long confinement, impulse driving their host bodies to escape. The stronger ones see it as a means to reinforce themselves, as a defense against any Hollowed or Reborn that may come after them.
The more common public is viewing the World Tree like it views other worlds in the galaxy, even if travel to the World Tree is much easier than finding passage on a ship. Many do not believe in magic or psychics or any supernatural things, but they accept that there are things they cannot explain. Some of the lower classes in squalor seek to escape to another world where their life is better, trying to peddle simple devices in lesser-developed areas for riches... but this has only revealed how bad cases of BCA Syndrome can get.
A growing affliction amongst the population is called BCA Syndrome, short for BroadCast Addiction Syndrome. More and more people become jittery, paranoid, and eventually hallucinate or go comatose when deprived of a constant source of information. It does not appear to be communicable in the standard ways, and so far no offworlder has contracted the Syndrome. That doesn't mean many other worlds aren't wary of just that happening!
Olympus 2.0 is a high-tech setting. Space travel exists, but it is 'slow' FTL that makes it very difficult to develop extrasolar colonies very heavily. Energy weapons exist, but are only marginally more powerful than advanced projectile weapons and much more expensive. While advanced 3D printing is achievable, it is very expensive to print anything but basic plastics and metals, so true post-scarcity has not been achieved, and most of humanity gets by on soy-protien, holovid entertainment, and drugs. Lots of drugs.
Even the poorest of citizens has a cortical stack, technology that records their mind. New bodies, or 'sleeves,' are expensive but not out of reach of a decent wage, though it would be equivalent to buying a small house. In theory everyone is immortal, but in practice very few live again after death, and the cortical stack is far from indestructible.
The Reborn is the name that has been given to those people whose selves have been infused with an ancient soul. The gods are some of these, but ancient heroes and monsters also bond with a fragmented human soul. These are divided into Sleepers, who have impulses and partial powers, and Awakened, who have at least fragmentary knowledge of what they are.
Reborn do alter their host bodies to look more like their ideal form, and do so subconsciously, but are limited to the humanoid phenotype. If Cerberus were to become a Reborn, for example, they would gain increased physical abilities and canine-like attributes. Their shadow might tend to have three heads, but their actual body would retain only one head.
Reborn can have fantastic powers, but in the age of reason their abilities are usually subdued and more subtle. If a Reborn is moved to another body, that body will change over the course of a few weeks, but the shock of moving to a new body often represses their knowledge of who they are. Reborn cannot be backed up and successfully restored though. Their essence will either flee to another body and become a different person, or die entirely, should their stack be destroyed.
Awakened Reborn, even those who know who they are, always end up a fusion of their host's original self and their essence. Even if the god or supernatural is dominant, the host's personality influences them strongly.
Hollowed are hosts that have had their soul damaged. This leaves them hungry and eventually mindless, like a zombie. They are usually not effective against a trained combatant, but their fragmented minds can end up terrifying people. Worse yet, some of them are remnants of Reborn who were moved into a new body suddenly, and have supernatural abilities remaining. Some of them are even remnants from the underworld, seeking the soul that they've lost to the living. These Hollowed are much more dangerous, as they are difficult to kill permanently.
The Reborn gods are almost all in lower class bodies, and do not have the enormous amount of funds it would take to purchase the actual Mount Olympus on Earth. Many of the gods have fragmentary memories at best, as well. Despite this, Olympus 2.0 exists as a dark network meant to communicate with other Reborn and bring them up to speed.
This has not gone as planned. Even before being merged with mortal bodies, the gods of ancient Greece were always petty and selfish creatures. Feuds are beginning to flare up between the gods again, and the more manipulative are starting to jockey for better positions once the whole matter of the soul leakage from the underworld is fixed.