Ether 15:13

And it came to pass that Ether did behold all the doings of the people; and he beheld that the people which were for Coriantumr, were gathered together to the army of Coriantumr; and the people which were for Shiz, were gathered together to the army of Shiz;

Ether watched everything the people did. He saw that the people who were for Coriantumr came together to Coriantumr’s army. And the people who were for Shiz came together to Shiz’s army.

Ether watched everything unfold. He saw supporters of Coriantumr gathering to his army, and supporters of Shiz gathering to his.