The front character looks like a cross between Kyu Kusanagi/Terry Bogard KOF95'ed. I know it's the same company (back then) and probably same artist, but the similarities man!
Mutation Nation pre-dates Final Fantasy V and its creation of Beastmaster's armor design by a solid year.
having said that, the character in question is wearing bone/skeletal themed armor (complete with ankhs on the pauldrons and a large bird skull on the chest) and the only real similarity to FFXI's BST AF/Relic armor are the ram horns.