Saleen had that idea at the last moment. After he found out what Nailisi did, he gave her a lecture and used his family badge to make Nailisi understand that she was still his summoned creature. She could not make decision as she wished and ruin his plan.
After that, Saleen brought Nailisi to see Lex for a discussion on how to solve the problem. When he saw Bifano standing in the plaza of the central hall, he immediately had a new idea. Walking past Bifano was something a normal mage would not do. Bifano was a swordmaster, after all, and his response speed was too fast.
There were three strong hatchet men around Saleen though. Everyone of them had the ability to suppress Bifano, so he naturally had no worries about his own safety. Using the water current from his calabash to tie Bifano up, even a sorcerer would not be able to dispel the water current. Saleen's mind was at ease.