Nie Mingjue is the general who leads the Sunshot Campaign to stop the Wens who are on a killing rampage. (They'd just killed most of Jiang Cheng's and Wei Wuxian's family and destroyed Lan Wangji's home.) So he definitely uses his fighting powers for good, but it still does the damage it does. Meanwhile Nie Huaisang doesn't fight in the Sunshot Campaign at all, but he also ends up damaged in a different way. Nie Mingjue reminds me a lot of Hakouoki and the way being a warrior eats the characters up from the inside, but Nie Huaisang doesn't get to opt out of wartime trauma either just because he chooses not to be a fighter.

If you're not into tv there's also the novel, but I keep being thrown out of the novel because Jiang Cheng is so much more of an asshole in it.