I wouldn't say he's a-list, but the Storm marriage undoubtedly boosted T'Challa's profile, and helped make Volume 4 a success. It's often critiqued, but there's no doubt that it sold well.
Originally Posted by Lightning Strykez!
Cameos from any of the Big 4 (Cap, Iron Man, Hulk or Thor) would be essential.
I'm not feeling you here. At all. Nick Fury, yeah, but Black Panther isn't so deplorable that he can't stand on his own two feet. And a cameo can have the opposite effect, btw. Like Howard Stark in Cap, it can derail the film a bit and send the message that the character isn't worth telling without other heroes around.