The introduction of Christian Bale as Gorr the God Butcher in Thor: Love and Thunder will give the Odinson his most dangerous enemy yet. But in addition to that, his presence also has ties to another popular Marvel character, Venom.
Gorr is a vengeful being on a mission to vanquish all deities in retribution for their indifference towards the suffering of mortals, and is able to take on individuals of such power due to his primary weapon, the wonderfully doom-monikered All-Black the Necrosword. The blade is formed from a black mass that bonded with Gorr after he witnessed a battle between its previous owner, the primordial entity Knull, and the final survivor of an army of golden-armored gods that the abyssal deity had slaughtered.
Wielding All-Black, Gorr is afforded a host of powers including superhuman physical capabilities, regeneration and nigh immortality, but it’s the sword’s origin that’s most important here.
Knull is the progenitor of the Klyntar, a race of amorphous, shapeshifting parasites who can fuse with other lifeforms to possess or corrupt, either way bending their hosts to their will. They are, of course, better known as symbiotes, of whom Venom is the most prominent. All-Black was the first symbiote, formed from Knull’s own shadow that was cast by the first light of creation then tempered with the power of a slain Celestial, and remains the most powerful of the creatures.
Symbiotes are yet to appear or be referenced in the MCU due to their rights falling within the remit of Spider-Man-related Marvel properties still controlled by Sony. However, agreements allow Peter Parker himself to crop up at the side of the Avengers every now and then, so there’s no reason that the wall-crawler couldn’t one day appear in a cool new black suit, with all the associated chaos to follow. And should Thor: Love and Thunder portray Gorr wielding the dark blade and maintain its comic origin, it could provide an opening to introduce Venom and the other symbiotes to the shared universe.