Mario & Luigi: Superstar Saga - Final Battle - No Damage, No Items

I couldn't help but return to this perfect game. Won't be the only time either.
In this video, I run through Bowletta and Cackletta's Soul at Lv. 40 without taking any damage or using any items. This also means I remain at 1 HP throughout the whole Cackletta's Soul fight!
Note: I used my Walkthrough save file for this video.