from the wiki
"The final battle in Monstro, while playing the same, is now recorded within the Journal as a mini-game. Also, the Shadows defeated during it drop EXP, unlike in the original GBA version."
I've started with Yukiko and am adoring her fighting style. I'm always impressed with people who can play competitively! I've never tried so I'm pretty hesitant about it...
Ugh, I want P4G so badly but I don't own a Vita either. I might just buy it like you have, before it gets rare.