There is a thread about my concerns, but it doesn't really reassure me unless I get feedback about the concepts used. To fans familiar with Fate series, I definitely took inspiration from the whole thing. I am a forger and not a creator, to remind you all. Honestly saying that I can't create out of my own. All I can do is reshape the idea itself to something else, but the foundation of such ideas belong to various creators' works I've become fascinated with. People are born in the Human World and die in it after given life. Among them are people who returned from what can be viewed as the place where the dead go after death. These returners are people whose souls have left the Human World in varying lengths of time and spent that time on what is called the Dark Side. It is referred as dark, not due to lacking light, but having it be an unseen dimension dislocated from the temporal flow in the Human World. The Human World being made of worlds dominated by Humans throughout countless histories of civilization, as not all civilizations appear to be the same or linear with one world to the next. Returners are said to be people who have developed unnatural abilities in their lifetime, but a Returner's lifetime is divided into 3 types. Spoiler: Type 1 Type 1 are those disjointed from their original timeline in the Human World due to staying in the Dark Side for some time. Type 1 suffer the cases of being spirited away, coma, or stillbirth for a short time. These Returners are borderline Type 2, except they retain their human sensibility, excluding change perceptions they have on the Human World. They return to their bodies in any random moment after stepping in the Dark Side, and in their return comes with anomalous powers imprinted in them after having come contact with AKA. Spoiler: Type 2 Type 2 are those who have died in the conventional sense, but returned to the Human World as something else entirely. These Returners are classified as creatures bordering between the Human World and the Dark Side. They are called by Humans by many names throughout the eras, but the standard definition to them all are as Shades. Shades have existed since the dawn of time, some residing in the Human World in peace, or with some forced to return back to the Dark Side due to causing large damages towards Humans. Erasers are sent to reverse the flow of events affected by Shades by pushing them back to the Dark Side through force, and at rare times, coercion. Shades also possess abilities greater than Type 1 or Type 3, thus, the reason why Erasers are sent to deal with them. Spoiler: Type 3 Type 3 are those whose bodies and souls have drifted to the Dark Side, and suffer the similar effects as Type 1 and Type 3. These Returners are in between Humans and Shades, since they possess human minds, but having physically spent time in the Dark Side had left mutations on the body. Some of them become Shades in the gradual years, some soon than most due to accelerating the spread of Darkness, but others remain as Humans for a long time and die like Humans. Now among the Types 1 and 3, come the Daemons, who are Returners having form a covenant between themselves and Mag Manna. It is through Mag Manna there exists magic, which are remnants of old non-human civilizations of the world before humans started dominating in the present timelines. Mag Manna is the contradiction within the human collective in the Human World. It is desires the complete annihilation of magic using magic itself. Daemons are Returners who have become threats to their respective worlds, or have chosen to become Daemons for personal reasons, which Mag Manna does not care about. These Daemons are classified differently in different Orders. Orders varying from Human-based games are placeholders for Daemons to regulate their rankings in power to avoid disturbing the Human World when sent by Mag Manna to Dark Spots to collect Grain back to it. These Dark Spots are places in the Human World accumulating a large amount of Grain, which are crystallized miracles left behind by Mag Manna itself or beings capable of miracles. Leaving uncollected Grain in the Human World would result in the Dark Side eroding the Human World through these Dark Spots transforming into Cradles of Darkness. Daemons are sent to keep this erosion in check or prevent them in happening in the Human World. The only problem in this are Daemons fighting over the Grain, since Mag Manna does not care how many Daemon there are, as long the Grain is collected or the Cradles of Darkness are suppressed. These little skirmishes are acknowledged by Daemons as Dark Battlefields due to having Dark Spots become their arena. Lord of Crimson Air who is part of AKA itself in threatening situations concerning the Human World sends Slayers who are amalgamations of murderous thoughts towards certain species; and some being the worst slaughters in the Human World brought back to eliminate their target. These Slayers appear only when the Human World are threaten by extinction, and multiple Cradles of Darkness are enough to threaten the Human World, resulting in the destruction of both Daemons and Invaders alongside the culling of humans in those areas.
I'm not the greatest Fate expert, but I did finish the original VN, Fate/Zero, and Fate/Extra (I've also watched FGO: First Order). As far as I can tell, your premise seems original and only vaguely reminiscent of the Fate series, so there aren't any problems with that. To be honest, though, I can't say I've fully grasped the concepts you described; there are quite a few confusing things here and there. Let me know if you'd like a full critique.
I’m the same type as you and I can tell you someone must know the Fate series well in order to recognize the origin of your work. You’re completely in the white.
Think the base premise is inspired by fate but there is nothing similar to the series with what you are planning to write. This should be fine
I don’t think you have anything to worry about. I’d like to point out that “50 shades of Grey” was originally a “Twilight” fanfiction. That got published with no reprecusions, you writing a story inspired by another story is totally fine.
I believe originality not only comes from the uniqueness of one's idea but also from the influence of many works. If you would you like you can read mine as well nekothecat wattpad