In spite of having just lost his sight, Paul still kicks all kinds of ass. Going full blown Blind Seer mode and is able to commands his troops easily, fly an ornithopter using only his prescience, and kill a Tleilaxu assassin who had his loved ones hostage.
But more than all that. The story ends with him becoming a myth. That is to say, a group of conspirators are sowing doubts in the Fremen population as to the validity of Paul Maud'dib's rule (being blind is cause for exile in Fremen culture). So in one fell swoop he dispels all doubts by going into the desert of his own free will while blind and having lost all prescient ability... and while there are sandworms in the fucking ground. It's no wonder that this causes a religious fervor, getting people to believe in him more than they already do. The death of a man, and the birth of a myth.
