Wrong forum, the Roleplaying forum is for forum based roleplays.
None the less, are you drawing Dark Fawful out of Dark Bowser? Because you can't kill the latter by just repeatedly attacking him. You have to wait until he becomes giant, dodge the attack that involves an army of dark Mario enemies trying to attack Bowser, and then punch him in the stomach to knock out Dark Fawful, who can be inhaled with the vacuum attack. That lets Mario and Luigi fight the Dark Star Core/Dark Fawful.
Then, take out the core's glasses and legs to make the Dark Star itself vulnerable to attack, and pelt it with Magic Window and the likes.
1.
Psychology
the acting out or performance of a particular role, either consciously (as a technique in psychotherapy or training) or unconsciously, in accordance with the perceived expectations of society as regards a person's behaviour in a particular context.
The RP forum is for you to engage in text-based roleplays with other users, sort of like a less board-gamey version of Dungeons and Dragons or something. It was pretty big back on NSider, the old Nintendo forums, and I think at least a few of us went there back in the day. Maybe not as big at other places.
Anyway, what attacks are you using? I personally kept fighting enemies in the castle until I got Bowser to End Boss rank which made a big difference. Did you get all the Blitties? (I think at least one enemy type was really rare and annoying). Broggy Bash and Mario and Luigi's Star Bros. Attack are hilariously overpowered, and I relied heavily on them to beat the harder bosses.
