Requirement

-no romance, may it be ponies, griffins, or fellow humans

-the story can be dark, and the non-con tag can be used. Just have to have zero hint of romance in it.

-no ecchi, such thing as 'mare in heat' are allowed but must not involved the protagonist in any sexual or implied sexual ways, even as a joke.

-the protagonist must not be a mary sue. the protagonist is just another inhabitant of vast world and must not outshined the original heros in anyway.

-the protagonist must existed as a human or a human character from other IPs. EQG human and humanoid furry doesn't counted as human.

-crossover with other story and such is allowed, but must not takeaway the focus from main world. The existence of the council of displaced is a no.

-majority of character must not be biped. That mean majority of main casts must not be anthro, minotaurs, stormcreatures, and abyssians.

Optional(don't required it but made story better if it do)

-slice of life/drama story

-longer than 2k words count

-marked as completed

Interesting.

7871977 Can it be M rated? Cause they're more adults than kids and teens these days.

Check out Hail to the King. It's hilarious. No, I don't care if it's currently on a lengthy hiatus. It's 100% worth reading.

-the protagonist must existed as a human or a human character from other IPs. EQG human and humanoid furry doesn't counted as human

I was going to suggest Hold It Together but then this rule appeared.

no offense to OP but damn that sounds picky as hell and eliminates a lotta stuff I can suggest due to the no romance and no human rules

There's also The Mighty Warrior of Epicness. A man Displaced into Gilgamesh from Final Fantasy*. Dunno if it hits ALL of your requirements, but it's a decent read.

*As in, the whole series. Yes, it's the exact same Gilgamesh in all of them. He's an interdimensional traveler, as per FF canon.

7872128
That looked like a fun misunderstanding comedy, thank!.
7872003
Yes, but rate M must not have any romance undertone.
7872540
I already read this story. A good story that suddenly gone into hiatus.
7872575
Well, my taste is in novels and comics is horned by hundreds of trash-tier j-fantasy and fine tuned to the point that it only accept stories specific ones.
7872697
Holy shit so many crossover.
And who is this guy? Why he called himself gilgamesh?

This is the real gilgamesh

7874860
There's more than one character named Gilgamash. The one they're talking about is the one from final fantasy. He appeared first in Final Fantasy V.

7874860
The FF Gilgamesh came well before that one.

Publishing date for Final Fantasy V: December 6, 1992

Publishing date for Fate/Stay Night: January 30, 2004

That's a 12 year gap, jsyk.