In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

They joined Mishe and Buzhen , made a surprise attack on Helu , and captured or killed tens of thousands .
He joined forces with Ashina Mishe and Ashina Buzhen , and made a surprise attack on the regrouping Ashina Helu , again defeating him and capturing or killing some tens of thousands of men .