Along with the first 8 character (He-Man, Skeletor, MAA, Beast-Man, Zodak, Stratos, Teela and Merman) I think Evil-Lyn is one of the core MOTU figure, both as female villain and second in command of Skeletor army (as she's often depicted).
The figure by itself look nice, reusing Teela's bdy without the armor and different color made her look pretty different. Likes the wicked sorceress / evil warrior helmet with skull and all, along with her curvaceous figure she really looked like a sultry amazon from some Frazetta painting and such classic Sword and Sorcery goodness. Bold corset, big curvy thigh, barbarian fashion animal pelt boots and dashing bracer really make her in line with golden fantasy imagery.
Fantasy cannot be fantasy without evil seductress babe, and Evil Lyn figure do her much justice for that part. Remove all mythos around it, and just by itself the figure you can guess she's the evil warrior chick!