Try to beat him at lvl 40 use Broggy bash (or what ever)
Stock up on heal-y thingys and
Have defense items on so thats all can really tell you so good luck!
oh heres how to dodge one attack
Bowser:
Dark Meteor Shower: use Y to dodge the middle and left meteors and if theres one on the right punch it and it will hit Other Bowser
Dark Bowser Has about 1000 HP after you knock all the 1000 HP he will cough out Fawful Bug then you Vacuum Fawful BE QUICK! Then attack Fawful's legs the attack the Dark Star the top of Fawful then after you do this afew times you own him! oh wait this parts easy but you have to press X to throw some final punches at Bad Bowser