When Leonidas first appears, he is a Bakugan with a large hunger for battle and stayed away from other Bakugan. All of this had changed when he battled alongside Valentin. He grew protective of Valentin and became close friends with him. He also lost his large hunger for battle and gained a sense of justice in return. He gets along well with other Bakugan, but is usually quiet and serious. However, Leonidas sometimes helps play pranks on Valentin, and like Valentin, is against people doing things against their will. He works well with other Bakugan and other Brawlers as well as when working with Valentin in brawls and outside of brawls.
Leonidas, unlike most ferocious Darkus Bakugan, is merciful, yet at times, can be willing to destroy an opponent. His lust to raze down an opponent only occurs when his opponent is and evil villain and/or a traitor of some sort.
- Mega Laser: Gives 200 Gs to Leonidas.
- Omega Eraser: Gives 200 Gs to Omega Leonidas.
- Doom Phaser: Gives 400 Gs to Doom Leonidas.
- Vortex Fiery Darkus: Gives 200 Gs to Doom Leonidas and takes 400 Gs from the opponent.
- Vortex Shadow Pyrus: Gives 300 Gs to Doom Leonidas and takes 300 Gs from the opponent.