It’s also worth noting that Sundar didn’t go on a roaring rampage of revenge kind of plan. His rebellion was more of the “y’all are dicks, so we’re going to go live over here now, and you can kindly fuck off kthx” kind, instead, and it’s a safe bet that the choice to respect Brunhilde’s final plea and show a bit of real humanity (in addition to Sundar’s own previous willingness to aid in the mistreatment of innocents) is why. The SC might have a different reason to lower himself to a despicable act like this, but it’s still relatable enough that Sundar can’t dehumanize the man.