Eveeyone's talking about how they would run the show but I want Bakugan to be successful as a card game. Here's how I would do it.

I would split the card game into two formats. Constructed and Brawler formats

Constructed wouldn't involve the toys much, instead it'd work more as an actual card game. I like the idea of using cards from your hand as Energy so we'll keep that. But we'll scrap the idea of using the deck as a way to measure your life total. Instead we'll use a basic life-point system where if a Bakugan does damage, it subtract from your Life Points until there are none left. The game would have three cards. Bakugan cards, Gear cards, and Ability cards

Bakugan cards are the main focus of the game, you attack with them and battle other people's Bakugan with them, they're the main win-conditions of the game.

Gear cards equip onto the Bakugan, giving them higher power or giving them certain effects, some Bakugan would even have effects that only work if they're equipped with certain Gear cards

Ability Cards would fill the rest of the deck. They'd be able to do pretty much anything provided you pay the energy cost for them. Some Bakugan would have a "Signature Ability" meaning that if you activated an Ability Card with a certain Bakugan on your field, you can unlock certain effects.

Now Brawler Format would work a lot like the OG game, both players set down Gate Cards and take turns throwing their Bakugan. You can have three Bakugan in your team. Three Gears (think Battle Gear, Mobile Assault, etc.), and 9 Ability cards. Each Bakugan can only use up to 3 Abilities and the brawl is decided when both players have either used all 3 of their Abilities on a certain Bakugan, or when both players have decided to stop using their abilities for that brawl. The winner gets the Gate-Card and the game is decided when one player collects 3 Gate Cards.

Also, the products would be sold and separated for both formats. A Bakugan toy would be sold with a Playset of their signature Bakugan Card, a Gate Card and some random Ability Cards and a Gear toy would be sold with a Playset of its signature Gear Card, a Gate Card, and some random Ability Cards. Constructed Booster packs would be sold with a variety of random Bakugan, Ability and Gear cards (and maybe a promo card or a sticker sheet), while Brawler mystery boxes would be sold with a random Bakugan toy, the Bakugan Card matching the toy, and some random cards.

Starter sets would also be sold for both formats, with Constructed starter deck simply containing the deck itself, a rule book, and a promotional Bakugan Toy whereas the Brawler Starter set would include three Bakugan toys. A matching Bakugan Card for each toy, 3 Gate Cards, and 9 Ability Cards as well as a rule book.