All Black The Necrosword first came into existance when the primodial entity known as Knull was first disturbed by the onset of the Celestials set about creating existence. Fashioning the jet black abyss of his own shadow into a mighty edge which could cleave through the divine, he set out to darken creation and bring back his void to replace it by killing any and all divine entities tied to the light that so irked him. Eventually fashioning his base of operations out of the remains of the first celestial he killed. Using its primal cosmic energy to better fashion his very first symbiote into a mighty cloak and armor shell with which to wage endless war upon all of existance. All-Black is a much dreaded and legendary weapon of millennial import having passed on from it's first user to other users over the endless eons throughout the cosmos. Legends of it springing up from one end of the galaxy to the other, as being said to have been the very tool used to carve creations first dawn from eternal night. Other fables go on to say that it was created by the Elder Gods of time long passed during times of the Big Bang, using it to carve out existence from the immovable nothingness.
More on saying that the World Slicer is the physical manifest of the darkness within the gods themselves. It's wielder being little but an empty husk, a mere slave unit piloted by it's own murderous will, or having been used to slay billions to a billion billion gods across the universe. All the same Nulls's personal symbiote passed down through history as an incredibly malevolent weapon that responds to overwhelming negative emotions of rage or the like.
All-Black has been used in countless millennia to kill the divine and imbibe on their deaths to feed the users power, killing the transcendent makes both it and its handler stronger but it also has the capacity to corrupt them into insidious, malevolent and otherwise warped beings. Truly darkened images of who they once were before coming in contact with it; as stated once by a cosmic equalizer that it demands a terrible price for its power, with a great many of its former wielders being driven to madness, killing their own brethren or brothers in arms over it. As Null was slaughtering the emissaries of the light, he eventually fell in battle with the godlings he despised so much. Crashing on one of the first worlds to ever spring forth life from it, it was then and there that The Necrosword would latch itself onto Gorr who would continue to use it for the purpose of wiping out every known deity who'ed ever existed or would come to be. As was it's original purpose, the annihilation of all bringers of the light in every corner of existence.
This ambition leading him to utilize plans implicated by Shadrak; god of bombs and fireballs of the Oghoghoan pantheon. All of which culminating in the construction; via the forced enslavement of divine beings, of the Godbomb which was powered and activated by The Annihilablade's essence. The plan did not succeed as it was absorbed by Thor who used it to kill Gorr, the Necrosword was left on the planet and thrown into a black hole by Old King Thor.
Years into the future the Necrosword would be retrieved once more by Old King Thor in order to aide him in stopping Galactus from destroying the Earth he became Necro-Thor and defeated Galactus using the swords power. Galactus was then given leave to consume Mars however it turned out that he had also consumed the Necro-Sword and now had it's power becoming the Butcher of Worlds. This was until Ego killed Galactus taking the Necrosword for himself and he became Necro-Ego. Loki watched while Ego killed Galactus and in a future vision it was seen that Loki would come to hold the Necrosword. Loki would challenge the then maddened and corrupt living planet as he ate the last of the Acanti in the dying universe, approaching the necroworld in the form of a simple earthworm who challenged him to a duel. The planet raged and riled shedding much of its planetary mass in a volcanic fury while his adversary remained unharmed by the end of which, now exhausted and without proper defense.
Loki would speak to the derided biosphere for more than ninety-nine years, eventually driving it even further into madness than it had already descended. What was left of the living planet relinquished the black blade to the victor, whom resumed his original form only now adorning the jet black blade as his trophy. Now ascending to his true form, loki took the name of Necrogod, the all-butcher and lastly... The End.
The jet black blade's main substance is primordial darkness which the user can conjure and wield at will. A more skilled user can reshape it into whatever kind of shape or form they can imagine; be it a shadowy cloak with which to garb oneself, create wings for flight, tether's or snares able to entrap mountainous or singularity spanning creatures, weapons and even semi-sentient to fully self-aware entities with portions of the shadow blades power.
A user who has bonded with the blade has their natural physical aspects enhanced to the point of rivaling the divine and other cosmic entities. Gorr utilized its powers to singlehandedly carve a bloody swath through armies and high houses of the divine and their respective pantheons with near ease. Giving him strength enough to best a galaxian creature who could wrestle black holes for sport, move and fly at or beyond light-speed to overtake his prey, was tough and reactive enough to resist both the physical and mystical onslaught of three time relative Thor's and had accelerated recovery able to heal after being struck by lightning more times than once by a younger Odinson.
All-Black also made its user incredibly long lived, the god butcher being more or less several thousand years old while remaining in his physical prime since the day he first picked up his primary weapon.
The blade can also bestow the ability to project and manipulate or greatly enhance any preexisting ability to cast forth energies of varying kinds. Gorr using it in his battles against the three Thor's and again by Old King Thor while fighting Galactus after needing more juice in his jump against him.
Divine Siphoning/Killing Empowerment
It's edge could be further sharpened and empowered by sapping deities of their life to feed the user their strength, the more gods killed by way of the blade and its fabrications. The more powerful it's weaponer would become as a result, but this effect isn't infinite as one must constantly keep killing gods and or other such transcendent beings as the swords power eventually runs dry over time.
Said weapons main and primary function is the ability to kill just about anything it come across, be it slews of higher beings worshiped as preeminent beings or the very metaphysical abstracts that compose of or even represent the universe in various ways. Despite their immortality or resilience to harm and even their very substance that defies the effects of mortality.
All-Black is a metamorphic weapon of devastating proportions without any true shape of it's own. But whenever the user deems it necessary they can unlock the malevolent Klyntar's ultimate power. Appearing as a massive dual ended blade capable of rending apart suns.
The most devastating facility of the Annihilablade is it's capacity to spread, infect and become the known universe as a whole. Whether it overwrites the current reality s a whole or subsumes it like a ravenous dark affliction is not yet understood. What is the case is that a wielder powerful enough to bring out the totality of the symbiotic blades power essentially becomes a living cosmos. A genius loci populated with living extensions of itself in the form of stars, planets, galaxies, black holes and the like. All of which is geared towards slaughtering enemies.
Formerly used by Knull, Gorr, Galactus, and an Elder Future Thor, Ego and eventually Loki.