Yusuf Zuck, although capable of flight, couldn't release his telekinesis nor could he fly high. Additionally, after ascending the mountain, he encountered several thrusts of force. This force was invisible, and although he clearly tried to fly upward, the force would push him away, impeding his progress.
About five or six minutes into his journey up the mountain, he finally encountered the first danger: a barrage of qi arrows formed by air currents. It seemed he had triggered some kind of mechanism, and he was hit by the qi arrows. Although the arrows didn't penetrate his body, they shocked him to the point of spitting out mouthfuls of blood.
After that, dangers became increasingly frequent: strange huge stones fell from the sky, bizarre spikes emerged from the ground, and there were even wind blades and flames, among other threats.