How to use igniz in the King of fighters 2001 neogeo

I verified this at gamewinners.com: You must set your Neogeo settings to console first. You can only select one of the hidden characters in one of the four slots where you arrange your characters or the game will freeze. Go to the ? box and select right to see the hidden character box. They are the bosses of the game. i hope this helps. I have used gamewinners a lot and they have never been wrong before.