I just realized something about Shen and Zed.
The moment they fight each other Shen has to kill Zed. This is because Shen would have to have been tasked with eliminating Zed as part of his duties in order to fight him. And it can't end with Zed escaping because Shen can sense him and follow him. So there will only be one final fight if there is one.
Just something I realized while brushing my teeth last night.