The end result that's needed for the Multiverse Avengers / Guardians of the Multiverse is that Killmonger becomes the Black Panther. They just needed to make that happen, and his more interesting part will be with the others, like how there's going to be both a regular Dr Strange and the bad Dr Strange according to the latest trailer.
I don't really care if this episode seemed to be going too well for him. If you did see the BP movie, you know he already made a full plan that went pitch perfect with no opposition right until T'Challa came back from the dead.
If I struggled to the end of my determination, to the end of my way of life with my followers, if the result is ruin, then this ruin is inevitable. Grieve. Shed tears. But you cannot regret.