1x29 - Bakugan Battle Brawlers

In the Doom Dimension, the Legendary Ancient Warriors of Vestroia prepare to test the powers of the Brawlers, seeing if they are worthy enough to save Vestroia. The Brawlers are separated and Julie is left with Gorem to face the Subterra Warrior, Clayf, and a shadow of her perfect sister, Daisy. With help from Gorem, Julie learns that she isn't her sister and she can only do the best she can do. Because of this, Gorem evolves into Subterra Hammer Gorem, and defeats Clayf.