Souji's design, while not a direct ripoff, just screams Sonia Belmont (in my opinion). The 2nd to last character on the top right row.
http://www.maql.co.jp/product/kagura_nw/character/souji.html The green was Sonia's primary costume color in her art, as well as the blonde hair, and "whip" as her main weapon further accumulates design relations. It can be none other than Castlevania Legends's Sonia Belmont that may have inspired that design.
Of course both characters are completely different people and their costume designs (even hairstyle) have significant differences, but the similarities are pretty obvious like Virtua Fighter's Akira compared to Street Fighter's Ryu. or Final Fight's Maki compared to Fatal Fury's Mai Shiranui.