WARNING: The following contains major spoilers for Marvel Studios' Eternals, now in theaters.
Marvel's Eternals is opening strong, with a deliriously huge cast of characters sprawled across time and space. Some of the biggest shocks to come out of the film are spared for the end credit sequences. This includes Kit Harington's hero, Dane Whitman, and a mysterious voice, which Chloé Zhao has now confirmed, but what he wants with Black Knight remains a secret.
At the university Dane and Sersi teach at, Dane is tormenting himself with whether or not to open a long wooden crate bearing the medieval seal of his family's house, seen earlier on the ring Sersi gave him. Opening it reveals a black sword -- The Ebony Blade -- and Dane is transfixed by the strange words written inside. Before he picks it up, a man speaks to him, asking Dane if he's ready for it. The voice is Mahershala Ali's first moment as Blade, but what he means by that stays unclear.
The Ebony Blade is a cursed artifact, a blade that feeds on the power of violence and bloodshed. Its history got fleshed out this year in Black Knight: The Curse of the Ebony Blade by Si Spurrier and Sergio Dávila, and it's a good enough reason on its own to draw out Blade, who also occasionally hunts supernatural threats beside vampires. There's also a possibility a new team-up is on the rise, and Blade just had his own Nick Fury moment.
MI-13 was established in 1996, in Excalibur #101 by Warren Ellis and Casey Jones. The UK's answer to SHIELD and The Avengers, MI-13 brings together every superhero on the other side of the pond, along with the occasional consultant, to stop the variously bizarre and supernatural threats they face. That can mean anything from an attempt by the Fae Folk to infiltrate the UK government to taking part in the efforts to stop the Skrull attacks in 2008's Secret Invasion event, by Brian Michael Bendis and Leinil Yu.
It's worth noting that Secret Invasion is filming right now, creating another potential link between these odd corners of the world. There's nothing yet to say that Blade has a potential Skrull threat on his mind, but he might be interested in keeping an eye on Dane and join him in handling stranger things than the norm.
There's plenty of hints that groups like the Thunderbolts and the Young Avengers are coming together to fill the void that The Avengers left behind. It's a big world, and there's lots of space for one more unique group of heroes to start gathering over in London.
The Marvel Cinematic Universe has made collecting oddities and shaping them into something sleek and fun into an art form. MI-13's original purpose in the comics puts Blade and Dane Whitman in a room together, and that could help the MCU blend that first story and its connections into something bigger and more approachable, like the Midnight Sons, Doctor Strange's anti-Darkhold and anti-supernatural evil team that's been getting the video game spotlight lately. Smushing it all together, fans could get a smooth path toward new allies for Doctor Strange in time for his sequel.
Without knowing Blade's motivations, much less having access to the formal synopsis for his upcoming return, it's hard to know for sure what he has in mind for Dane and his cursed black sword. The safest speculations are above, but as Eternals proves with its divisive and intriguing premier, the MCU isn't always interested in playing it safe anymore.