Black Knight is not the lead. Ikaris is lead. Dane is in this movie only because he is love interest of Sersi.
Black Knight character has very less crossover with Eternals.
Just speculating here, but they may be going the Wonder Woman route where an emotional love story with Diana, a goddess and Steve, a human was basically a central plot line. So he could very well be the (or at least one of) the male lead/s. Dane can easily be Chris Pine in this movie, just with his own history and superhero potential. I think the love story really helped WW resonate with the audience. This could be something great change of scenery for an MCU movie.
Eternals | Marvel Studios | Nov 5 2021 | Magnum-Opus by Oscar winner Chloe Zhao - Marvel's first rotten movie | Dips into the 40s on RT, B CinemaScore
in Box Office Discussion
Posted · Edited by medsommar
Just speculating here, but they may be going the Wonder Woman route where an emotional love story with Diana, a goddess and Steve, a human was basically a central plot line. So he could very well be the (or at least one of) the male lead/s. Dane can easily be Chris Pine in this movie, just with his own history and superhero potential. I think the love story really helped WW resonate with the audience. This could be something great change of scenery for an MCU movie.