Combination Impossible is the 31st episode of Bakugan: Mechtanium Surge. It aired on October 8th, 2011.
After Shun tells his story about what happened in his battle with Wiseman, the other Bakugan pressure Radizen when he is going to be able to combine. Radizen has become upset because he is unable to have a combination, he is approached by Roxtor but ignores him. He is later taken by Marucho who tries to cheer him up. The two of them are confronted by Wiseman and they battle against his Bakugan, Radizen is able to hold his own and beat the two, but when they combine he has a hard time. Radizen then fuses with Roxtor and is able to defeat them in battle.