This is a tribute to the Slime movie. Ultimately Benimaru has grown way more powerful than how he used to be and he proved that in this film. Even with the battle against a childhood friend forcing him to hold back a little, Benimaru just kept on fighting til he reached the top. Meanwhile Oolong doesn’t have ambitions like that. It’s a bit of a lazy match I’ll admit but hey, Oolong can transform. He just doesn’t have the same level of ability. Benimaru wins.