I know the ruling that giving Sozen a Chi penalty with a token from an action won't kill him, but here are a few questions still...
If Hida Sozen (XP) gets to 0C through a Focus effect (think: Strength in Shadow Style), can this kill him? Does the answer depend on whose action started the duel? (assume the duel was started by an action)
If Hida Sozen (XP) gets a Chi penalty that would normally get him to 0C while he has a nonzero minimum Chi (there are two typical situations: being in a Location with Hida Kuon (XP5), or having Kutetsu Kabe), and then later loses this minimum Chi, does that kill him? Does that only depend on what the source of the "killing" penalty was, either action or not? (say Sozen with Koutetsu Kabe gets, in order, a -3F/-1C token from Shosuro Adeiko, then two -1F/-1C tokens from Strength in Shadow Style, then another -3F/-1C token from Adeiko, then loses the armor; or, say the order is instead, Adeiko, Adeiko, Strength in Shadow Style, lose Armor; or, Adeiko, Strength in Shadow Style, Strength in Shadow Style, Adeiko, lose armor)