This is a case for the new Bakugan series, Battle Planet. It has room for all of the following:
3 regular sphere-shaped Bakugan from Battle Planet or smaller (may fit irregular shaped like Mantonoid Ultra, but with some difficulty)
3 spots for BakuCores (each can hold about 8 BakuCores)
2 spots for up to 40 cards
I like to use the BakuCore spots for my main team (2 per hole for each of my Bakugan), and have my Character cards in one Card spot and my Ability cards in the other, but you can use it however you like :)
EDIT: I made the lid slightly larger so it should be less tight and slide on and off easier. You may want to make the lid slightly larger or sand the corners of the bottom piece down if you're having difficulty.
Dazzle Light PLA
I sanded down the corners of the bottom piece just so the lid would slide on and off easier.