u probably already no this, but when u finish the game and go to the secret place, u can
get triple-star which is pretty awesome

if you finish the game get all the scrolls and you go to the secret map place you can get
thunder sword - thunder pow = sword pow, ice sword - ice pow + sword pow,fire sword- fire
pow + sword pow,ice bomb-ice pow+bomb pow,thunder bomb-thunder pow+ sword pow. And also
ghost pow (need to get ghost medal)-sleep pow+sleep pow