I'm pretty sure Nona was involved in the artwork as well though. Ogura Eisuke was definitely probably the lead and what I'm actually basing the rendering off of, but I'm sure they had a design document to follow when it came to the art.
Like I know for SURE this Saiki and Hwa Jai was done by Nona: [link][link] And Ogura did most of the others. All in all though, both of those cats are sick.
a lot of people fall to same mistake. firstly, i was mean official artworks not sprites (i not interest with them).
if u analyse his previous works such as "Samurai Spirits, Fuuun Super Combo, Ryuuko no Ken (AOF)coll., Garou coll., World Heroes, NGBC, etc.." u will easily noticed KOF XIII artworks belongs to him. that Nona only done previous titles (KOF 01,02,SVC).