This was not the first time Saleen had come across a powerful adversary. The most perilous encounter was when he had met the white deacon. Back then, he had been ignorant, so he had actually negotiated with the white deacon and managed to escape. However, this time was different. The deacons working under the oracles were not killing maniacs. They had clear motives in doing things, and thus, if they received certain benefits in return, their target might survive.
However, the black bishop from the inquisition was entirely different. There was no room for negotiation, and furthermore, Saleen had just killed his son.
At this moment, Saleen did not dare to go airborne because the black bishop could fly faster than him. If he had flew, the situation would be starkly different from what happened earlier on. He would not have the advantage of speed anymore.