Van hast du den Dragon Killer Key oder wie der Mist heist schon?Falls nicht hab ich hier was im gamefaqs.com Forum gefunden.Vielleicht kennst du es ja schon.

it's something that echang seems to have missed: you have to bring a Big Fish Bones (found in some of the gathering points. one is north of dart) to the ushinin behind the counter where erion is.

then when you go two stages to the left (the one with a monster-like prop in the ground which pushes you back) the same ushinin will appear and give you the dragon killer key (seems he used the fish bones ^^UU)

with it, examinate the machine left to the monster prop and you'll be able to play Tales of Dragon buster!!

to play the "original" version you have to go through the "tales" version first. the "original" means that luke will have the original game costume on and the sounds will change, but nothing more (also, i'm not sure bu it seems that costume is the one you'll get after beating it with the staff or the circlet)