Imu is incredibly proficient with his weapon, wielding it so skillfully that its movements can't even be seen or tracked, which is how Gerd loses her fingers at such a tremendous speed. Because Imu cut off her fingers, Hajrudin becomes completely enraged and charges at Imu. Stansen tries to stop him at the last second, but Hajrudin ends up losing his leg during the clash. In fact, they are not the only ones who lose body parts.
Witnessing Hajrudin lose his leg is what actually infuriates Zoro and drives him to launch his attack on Imu. When Zoro receives Imu’s counterattack, he doesn't just bleed; the strike is so overwhelmingly fast that Zoro immediately collapses straight to the ground. Later on, when Imu easily blocks Sanji’s kick and counters with black flames on his leg, the resulting explosion is absolutely massive; large enough to affect an enormous island the size of Elbaf.
