He could also be a boss for Story Mode. THE BOSS FIGHT.
WALUIGI:what is this place?
[Loud demonic laughing in the backround]
WALUIGI:who was that?
DEMISE:WHAT FOOL DARES TO ENTER MY REALM.
WALUIGI:WHO are you?
DEMISE: I AM DEMISE,KING OF THE SMASHUNIVERSE.
DEMISE:YOU ARE NO PROBLEM FOR ME BECAUSE YOU ARE WEAK .
WALUIGI.IT'S WALUIGI TIME .
SKULL KID:WHAT THE .
DEMISE:SO SKULL KID YOU HAVE DECIDED TO DIE AS WELL.
SKULL KID :BEHOLD THE POWER OF MAJORA'S MASK.
[SMASH] DEMISE IS SMASHED THROUGH A WALL .
DEMISE:IS THAT IT ?IT'S MY TURN NOW
A. Berserker Slash
<-A-> Heavy Swipe
A ^ Skyward Slash
A V Down Thrust
B. Demise Edge: Demise draws out his sword and slashes with it.
<-B-> Demise Thunder: Demise strikes the ground, causing it to shudder outward.
B ^ Demise Skyward Slash
B V Demise Spin Attack
FINAL SMASH LIGHTNING BLADE. DEMISE POINTS HIS SWORD SKYWARD AND A BOLT OF LIGHTNING COMES DOWN ON HIS SWORD.THIS LASTS FOR A MINUTE AND WILL DEAL INSTANT KO. but he will then be sealed away and switch to Ghirahim