Drago
Drago is Dan Kuso's main Bakugan and basically the heart of the entire Battle Brawlers series. He's best known as Dan's battle partner and constant companion, though he's also become something of a mentor figure—the wise voice that balances out Dan's more impulsive nature.
What makes Drago stand out is his lineage. He's a direct descendant of the original Dragonoid, one of only two Bakugan ever created, which gives him some serious credibility in the Vestroia universe. He's also one of the strongest species around, with the rare ability to evolve infinitely on his own without needing external help. In combat, he radiates intense heat from his body that can dissolve pretty much everything nearby.
There's an interesting contradiction to his character that fans often note: despite being this overwhelmingly powerful warrior, he's actually a pacifist at heart and gets impatient pretty easily. Still, when it comes to protecting Earth and Vestroia from threats, he's all in. That mix of raw power and reluctance to use it is part of what made him such a compelling protagonist throughout the series.
Content compiled by AnimeList.moe from publicly available sources.