Nakoruru : Select SNK Groove. After your third battle/match, your GP Points must exceed 60. Then the 'Here Comes A New Challenger' comes out. You'll fight NakoRuru.
Morrigan : Same as above but in Capcom Groove.
Akuma/Gouki : Your GP Points must exceed 80 before you fight the boss.
I have confirmed and tested all the above. Gambatte ! <IMG SRC="smilies/smile.gif" border="0">
Morrigan : Same as above but in Capcom Groove.
Akuma/Gouki : Your GP Points must exceed 80 before you fight the boss.
I have confirmed and tested all the above. Gambatte ! <IMG SRC="smilies/smile.gif" border="0">