Paper Mario 2 help?

[Brockoli]

I'm playing Paper Mario 2 and currently in the 4 and 5 intermission. Before I blindly waste shine sprites upgrading Yoshi a second time for the Shadow Queen, I want to know whether the second upgrade
A: Gives Yoshi an Attack Upgrade so Ground-Pound can damage the shadow queen.
and/or
B: Gives Yoshi an FP move that can damage the Shadow Queen.
Or should I just just upgrade Goombella a second time (the first coming from Doopliss)?
I don't want to waste BP on partner stat badges because I'll have Mrs. Mowz,
Bobbery, Vivian, Koops, and Goombella or Yoshi upgraded, plus 3 Shooting Stars and 4 life Mushrooms. More than enough to beat the Shadow Queen. Also, I'll have the quick change badge so I can switch out Goombella
efficiently the second turn.

 

[Missingno.7-4468]

Yoshi isn't worth upgrading for the Shadow Queen, in my opinion. I believe that I used Goombella for the Shadow Queen(But then again, I did master Goombella)...

So I would choose Goombella.

Oh, and Yoshi's upgrade only gives him ONE MORE Ground Pound without increasing damage, and I believe the FP skill is Yoshi Herd, or something like that, and I THINK it's multiple 3-damage hits.

Of course, I haven't played this game in years, so I could be wrong on something

 

[Thordainhammer]

I used Vivian for the Shadow Queen. She did decent damage and as I recall had a good way of hiding when the Shadow Queen's biggest attacks came along. I never really understood the goombella hype, but if it works then go ahead.

 

[Brockoli]

I checked on Super Mario Wiki and its official that I should use Goombella.