Complete the games in single player mode as rugal and save the game,load the game,hold start and L1 and press any button (Omega Rugal) 
Submitted by Steven Lim Peicong

BONUS CHARACTERS

Highlight the normal version of the following fighters at the characters
selection screen , then hold L1 and press any button:

* Evil Rugal Berstein
*'95 Kyo
* Real Bout 2 Terry Bogard
* Real Bout 2 Andy Bogard
*'94 Joe Higashi
*'94 Ryo Sakazaki
*'94 Robert Garcia
*'94 Yuri Sakazaki
*Evil Yashiro
*Evil Shermie
*Evil Chris
*Real Bout 2 Mai Shiranui
*Real Bout Billy Kane