The climax works because victory occurs on three levels. Caine defeats the bodily threat represented by Berne. Shanna survives by becoming Chambaraya's avatar, defeating the emotional leverage Kollberg used against Hari. He then attacks the story itself, using the broadcast to expose manipulation and denying the Studio the ending it contracted him to perform.
Ma'elKoth's displacement to Earth prevents the assassination from becoming a simple meeting of hero and villain. The emperor has spent the novel identifying Actors as invaders from another reality. By crossing into their world, he becomes proof that the border can be breached in both directions. His new identity as Tan'elKoth leaves the metaphysical conflict open for later books.
Hari's paralysis is the price that keeps the ending honest. Caine's adventures have been sold as pain without lasting consequence because the Actor can return to Earth. Now Hari carries the damage home. He wins control over the moment but loses the bodily freedom on which Caine's legend was built.