Zhylaw, Lord Marshal (Chronicles of Riddick) vs Black Panther (MCU)
Victory by death, must be H2H-only.
Unlike the fight with Riddick, BP gets no outside help and must kill him in H2H combat, it goes both ways and the same is true for Zhylaw.
Round 1 - No necromonger superspeed, straight H2H fight, BP can't wear his mask, no vibranium claws.
Round 2 - Necromonger superspeed allowed, BP can wear his mask and has vibranium claws. (If you think this is unfair for Lord Marshal, then he's allowed to use his spear.)
T'Challa in Round 1. Zhylaw's really only got his speed, and without that he seems to be a normal guy. T'Challa is roughly equivalent to Cap/Bucky, so he's got that in the bag.
In Round 2, Zhylaw's got a much better chance, but his bull rush will only charge T'Challa's suit, and it won't take long for him to get used to his timing imo. A quick energy pulse would end it as I see T'Challa closing the gap before he can go blue blur again. Also Riddick seemed to be able to look directly at Zhylaw's soul self as it ran ahead of him, so T'Challa could potentially see it as well.
Riddick was going to lose the fight, if Vaako didn't intervene Riddick would have died.
Riddick's sole attack was a surprise Shoryuken that only landed because the Lord Marshal underestimated Riddick's resistances, he would have literally been beaten to death if not for Vaako and Jackie.