How come I didn't see those 2 fighters Bisho and Claman in the Arcade? Could they had being Secret Bosses, who can only fight under some conditions? I wonder???
It seems to be a hidden boss added in Konami Arcade Advanced. It appears when you enter the Konami code on the title screen of the GBA version of Yie Ar Kung-Fu and defeat Bruce. And it's available in multiplayer mode right from the get-go! (DeepL translation used)
It is included in the Konami Collector's Series:Arcade Advanced for the Game Boy Advance! Multiplayer play is possible with just one piece of software if you have a Game Link Cable.🧑🤝🧑
You can play it if you have the 「Konami Collector's Series: Arcade Advanced」 for Game Boy Advance and a GBA Link Cable.😆 Only one GBA cartridge is required for communication.