Proxima wins. She only lost 1v1 to Wanda and needed a team effort from Cap, Black Widow, Falcon, Okoye and Wanda to beat her the other times, and none of them did it purely HtH. She has the superior base stats and has the range advantage with her spear. She can keep out of range of a chi punch and tough enough to shrug off a hit or two. The AoE is only going to be an annoyance.