They should add Dark Star core back to Paper Jam! You'll fight Dark Star core 2 times. The first time as part of the story, another time as a secret boss. After the first time you fight it, it will be paperizd and gets 6 layers. In both battles, at half HP, (Or with 3 layers left in the secret fight) It will turn into Dark Bowser and gets new attacks. If you don't Find the Dark Star core's secret hiding place after the final boss, You'll get the bad ending. Beat him and you'll get the good ending. Nintendo will be proud of this idea. Don't you think? Also a remix of Dark Star core's theam plays in the backround.