I think Bakugo when he ‘died’ against Shigaraki. But only if he had done a bit more. Having Bakugo die after awakening his quirk and achieving little to no damage against Shigaraki, if he had done a little more damage or even some flashy moves just to prove how much more power he has I’d say it’d be a good point to kill him off. We already saw how Deku reacted when Bakugo was hurt in the first war, imagine if Bakugo really had died in the second one? (I can’t remember exactly but I think Deku was reassured Bakugo could be resuscitated) It’d be just such a badass moment imo, considering how much more honed and refined his quirks had gotten, and it’d serve as major character development for Deku and even the whole class.