Doing some digging on the character, I'm sure it will start out that way.
The latest hero to join the MCU has a long, strange comic history. Here's what you need to know about Kit Harington's Eternals character, Black Knight.
nerdist.com
From what I understand, In the comics Dane Whitman is just human. But when he gets the Ebony Blade he inherits its powers and becomes the Black Knight.
"Although the Ebony Blade is powerful, it has one big drawback. The sword is cursed with the blood of all those it has killed over the centuries. It slowly drives its owner mad."
That sounds awesome.
"In the comics, Dane Whitman is not an Eternal. But he does have a connection to those immortal beings. During his time as an Avenger, he fought side by side with the Eternal sorceress named Sersi. The two quickly became romantically involved, and Sersi’s fellow Eternal Ikaris — soon to be played by Richard Madden — mentally bonded her and Whitman together."
So who knows how they are going to make it all work. But the Black Knight sounds like a cool character that could be a big player in the MCU going forward.