The '12 Years a Slave' actress, 41, stars as a terminally ill patient in the monster apocalypse horror prequel who is in a hospice when the film starts, and said the role helped her deal with her shock over her 'Black Panther' co-star and friend Chadwick Boseman - who was killed by colon cancer in 2020 aged 43.
Lupita told People: "It was scary to have to go there... (the character) is really facing their mortality, even before this apocalypse takes place, and whose life is slipping between her fingers".
"That was daunting to have to go there, psychologically and emotionally".
"In the end, it was actually very therapeutic because I had just experienced not too many years ago the death of Chadwick Boseman, which shook me to my core".
"I definitely was thinking about that a lot".
"What I came to realise is that it's really important to be reminded of our mortality, because then we live life just a little more intentionally. "When we think we have all the time in the world, we can really take people for granted and experiences for granted".
Chadwick died before filming started on the comic book sequel 'Black Panther: Wakanda Forever', though Lupita reprised her 'Black Panther' role of Nakia in the movie.
The actor had kept his colon cancer diagnosis secret during the filming and publicity for 2018's 'Black Panther'.
Lupita has repeatedly paid tribute publicly to Chadwick since his death in August 2020, marking the three-year anniversary of his passing in 2023 by sharing a photo of the two on social media alongside the caption: "Death is hard to understand, maybe even harder to accept. But the love generated from the life he lived will fuel every anniversary marking his absence.
"Chadwick may no longer be in our photos, but he will always be in our hearts".