Coriantumr's effort to strike off the head of Shiz was all the strength he had left. After seeing Shiz struggle helplessly, Coriantumr knew it was all over and he collapsed into unconsciousness.
Of course this is not quite the end of the story, either for Coriantumr or for Ether. Even though Ether finished his record he did not make contact with the last surviving Jaredite besides himself. He knew that since the Lord had said Coriantumr would be the last survivor of the Jaredites something would have to happen to Ether that would leave Coriantumr the lone survivor to fulfill his lonely assignment predicted in Ether 13:21.