Considering Mephisto has long been a fan favorite with Marvel fans and has a history of raising the dead, it wouldn’t surprise me if Marvel tapped Sigourney Weaver for the role.
Mephisto, while typically portrayed as a male, is a demonic immortal created by Marvel with real life roots based in German folklore.
In fact, I think if you recast any female actress as Mephisto, that’s who you do it with!
While undoubtedly popular, Mephisto has had limited affiliation with The Hand, who, believe it or not, actually answer to a different ancient demon in the Marvel universe.