You will need Donkey Kong and Yoshi.
in wario stadium
Save him from the top tower.
Mario Super Sluggers is better. You can use almost all Mario characters, including old ones from Superstar Baseball, and have day/night stadiums.
To the green koopa in Wario City
no you cant
The POW Ball.
in dk jungle (in the tresure chest that Wario can OPEN
You need to be DK and climb up the vines.
Save him from top of a building {you need donkeykong to climb vine}
In Mario Super Sluggers, my best team is, Mario, Luigi, Yoshi, (Mario in middle outfield) Peach, Petey, (Peach pitcher & Petey catcher) Bowser, Baby Mario, Wario (Bowser first base, Baby Mario second Wario third) Bowser jr. (short stop). Those are my secrets.
turn into wario, and press a when ur near a treasure chest or a garbage can
how do you get wario on Mario super slugers