In a period when dubious anime-licensed video games flooded the Eastern markets (or "The Great '90s Import Gamers Nightmare" as we cool kids used to call it) it was often hard to distinguish between good and bad Japanese titles - especially when the cover art featured your favorite manga or anime character in a cool pose, crippling your good judgement. However, if the producer of said licensed game was Hudson Soft, there was a strong chance of it being a worthy investment.
Kishin Douji Zenki or "Demon Child Zenki" was a shōnen manga that ran from 1992 to 1994, featuring the misadventures of the priestess Ozune Enno and the guardian spirit Zenki in their fight against the demon goddess Karuma. It was popular enough to warrant an OVA adaptation and of course, video games soon followed.
1995'sKishin Douji Zenki: Battle Gaiden! is an action platformer not unlike Hagane with stunning graphics and some neat special moves. The game itself is very import friendly, but thanks to Dynamic-Designs it is now 100 percent translated into English, making the plot clear to Western audiences.
You can grab the translation patch from right here and use it in your RetroN 5 or Retro Freak along with a copy of the original game. Just make sure you don't accidentally buy one of the other two Zenki games that have also been released on the Super Famicom, as they're not worth bothering with.