Ashina Helu
As Su continued to advance to chase after Ashina Helu, he encountered snow storms, and when his subordinate generals suggested that they halt until the weather got better, Su pointed out that Ashina Helu would be surprised that they were continuing to chase him through the snow and could thus caught be surprised. 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.