The King of Heroes. Son of the Gods. Gilgamesh is undoubtedly amongst the high tiers of the Nasuverse. Gilgamesh has waaaaaaaay too many abilities and haxs that it's almost impossible to talk about everything he could do. So I would try my best to explain some of his abilities, haxs, and where he scales.
To start with the basics, Gilgamesh own the Gate of Babylon.
This is a dimensional storage that stores every single treasure the world owned in the past, present, and even the future. This includes weapons and Noble Phantasms as well.
And it contains infinite weapons, treasures, and Noble Phantasms in it.
Gilgamesh can also see the past, present, and future with his eyes.
The name of the ability is called Sha Naqba Imuru.
He is also able to see all possibilities from different parallel worlds.
And even everything in creation to its tiniest relevance.
It's also impossible to deceive or lie to Gilgamesh because he can see the truth of all things even if you have multiple layers of resistance towards it. It wouldn't matter.
And with that same ability, he can take the best possible actions in any given situation. This means he would never make mistakes or wrong decisions in a battle(Shirou got lucky nerfed Gil never used it against him).
Gilgamesh also possesses a weapon called Enkidu. Named after his best friend. Enkidu is a chain that paralyzes and binds gods or any divine being. He renders their abilities useless once he catches them in it.
Gil is also able to destroy concepts with ease.
He's also an expert in Necromancy. He is able to summon the dead to do his bidding.
Since Gilgamesh possesses every Noble Phantasm in his GOB, he would also own Gae Bolg. Gae Bolg is a cursed spear that reverses the cause and effect of an attack. This means that before the spear is even thrown, its effect has already taken place. It's absolutely unavoidable
It even bypasses conceptual defences like Rho Aias,
As a servant with A-rank luck, Gilgamesh can manipulate his fate to avoid causalities such as getting his heart pierced by Gae Bolg despite Gae Bolg's ability to reverse cause and effect.
He also possesses a replica of "Black Barrell." A weapon that forcefully instills the concept of "natural life span" in an immortal being. He used this against beings who lacked the vision of death.
Gilgamesh also possesses the "Seventh Holy Scripture," which is conceptual armament that negates the concept of reincarnation by overwriting it with "many layers of dual concepts of reincarnation criticisms and eternity without providence."
He also has a 5D invisibility cloak that hides his presence on a 5D scale. This is for his normal base version that didn't possess higher dimensional existence.
He also has this Daemon-like ability that passively deflects attacks back at his opponents.
Because Gilgamesh was 2/3 God and 1/3 human, he was a higher-dimensional being similar to the Gods.
As a Demi-god, Gilgamesh possesses crazy and absurd immortality and Acausality(type 4) since he operates on a different and irregular system of cause and effect than regular causality. The rules and laws of humanity do not bind him.
This is the reason why Gods can always come back from the erasure of their hearts and souls.
They can even come back after having their origin/source erased.
And mind you, an Origin or "Saint Graph" contains the fundamental information of a person and acts as a very concept of that person from which all functions of the person are derived and dictates all functions of that person.
Yet, Gods can still survive after getting their's destroyed. They can even remake another Origin for themselves.
Gilgamesh also has the ability to make himself more powerful regardless of his situation by breaking the seal/limits of his source(bs power boost, lol).
Gilgamesh also can't be corrupted. He was able to completely negate the effects of all the world's evil due to his massive ego.
And was in fact, completely ineffective. Nothing can affect his mind.
Gilgamesh also possesses the "Ten Crowns," which passively reverses any injury or event that has occurred into things that never happened.
Gilgamesh also owns the Holy Grail (which the chad uses to drink, lmao).
The Holy grail is an omnipotent goblet that grants virtually any wish you want (It does go to show how damn careless the chad is).
When Gilgamesh uses his Ea, he fucks everything up, literally. It grinds at the laws of space.
Its distortion alone exceeds physical laws.
When it's being swung, It turns all things in creation that had meaning into things that have no meaning sending them into a void of nothingness and chaos which they originated from.
As for where Gilgamesh scales, he scales pretty high. Gilgamesh has feats, statements and abilities ranging from Universal to Outerversal+ level (he is outerversal fyi).
Universal+ Level
Gilgamesh destroyed Iskandar's Reality marble.
A Reality marble is an infinite Universe.
Gilgamesh>Reality marble~Universal
Low Complex Multiversal+
It is stated that Gilgamesh's Ea is greater than Artoria's Excalibur,
And this is proven to be true when Gilgamesh overpowered Artoria's Excalibur using Ea (though Artoria was nerfed, but you get the point),
Excalibur is so mighty that it could destroy Gilles' summoning, that was stated to be an extradimensional evil god.
| Gilgamesh Ea>Saber Excalibur>Gilles’ summoning~Extradimensional(Tier 1)
Complex Multiversal
Gilgamesh casually toys and mocks Altera during their battle in Fate/Extella.
The same Altera was stated to be capable of destroying the moon cell without even using Regalia.
The moon cell can cut through 8 dimensions to defend the moon cell core. It's stated that the moon cell core is a higher dimensional existence compared to the moon cell itself, making the core 9D at least.
| Gilgamesh>Altera>at least 9D moon cell core>moon cell core.
High Hyperversal
In his CCC form, Gilgamesh was relative to BB, though he was weaker overall,
BB has the power to manipulate the imaginary numbers of space,
The Imaginary Number Space(INS) is a higher dimensional space that cuts through imaginary/complex numbers. As opposed to normal reality, which is constructed through real numbers, complex numbers are said to have the same cardinality as real numbers,
In Fate/Strange Fake, Gilgamesh was about to destroy Earth,
The Earth in F/SF runs on quantum mechanics and is also stated to have a cosmological scale compared to a quantum multiverse.
(I would put the link in, but then the post may be taken down. Anyways.)
Using Hilbert's theory of space, Earth in Nasuverse has several higher dimensions, meaning its likely to have infinite-dimensional. This makes Gilgamesh High Hyperversal.
Gilgamesh’s Enuma Elish is stated repeatedly to have the power to destroy all of creation and all things that possess shape. With its attack potency surpassing the earth, reaching into the world.
The complexity of the Nasuverse cosmology stretches even deeper as Nasuverse concepts of the universe are layered infinitely.
Which allows for higher levels of the same concept, such as the concept of death,
...with every concept in its primordial state being stated to be absolute and platonic, foundating all possible functions of lower concepts. This should include higher dimensions as well,
This makes Gilgamesh with his Ea, Outerversal level.
Enuma Elish grinds at the laws and concepts of space.
...and after Ea has sent everything back to the origin of creation, the sword is able to recreate its own truth that overwrote the original one,
That makes Ea Outerversal+
So yeah, Gilgamesh is pretty darn OP. Respect to the King of Heroes.
Thanks!!!