LBX: Little Battlers eXperience Vol. 3 World Changer (manga)

To save his father, who is being held hostage by the nefarious Cillian Kaido, Van must win the Artemis Tournament to secure the main prize—the only thing Cillian will take in trade for his dad. But his next opponent in the arena is a fierce one...Cillian’s grandson, Justin Kaido!