Since I wanted to defeat the last Level boss character in The Gauntlet challenge (found in Challenge Node), I decided to spend a few hours leveling up the Mario Bros. from Level 45 to Level 51. It was recommended by the Emoglobin to challenge the Level 7 boss at Level 50, as well took its advice to level up in the Airway section of Bowser's body.

Since The Gauntlet challenges limits the items I use, I need to be more careful not to consume many special points (SP) if I am to face the last Level boss character, as I have to defeat previous boss characters one by one before confronting him.

If I continue to have problems with the last Level boss, I will need to level up the Mario Bros. even more, perhaps to Level 55 or even 60. I believe the maximum Level is 99, and I can imagine it would take me several days and repetitious battles to reach it. I did the same thing with most previous RPGs I played in the past.