A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 22 February 2015
Hello,
I play an unstoppable death, for example Serenity, and kill my opponent's personality. Can he interrupt with A Good Death?
I'm not really sure aout when the unstoppable trigger ends, and if a Good Death is on the action timing, or the death timing. My guess is you can't.
A Good Death Interrupt: If the action is another player's, after it destroys your defending Follower or Personality, give your target Personality +2F and Resilient, and gain 2 Honor. (Once per game per card, a Resilient card does not die in battle resolution.)
Serenity Unstoppable Battle, : Target your unbowed Samurai. Ranged Attack equal to his Personal Honor. (Other players cannot Interrupt Unstoppable actions.)
Thank you!
Alex Jones (rules official), 23 February 2015
Hello,
I play an unstoppable death, for example Serenity, and kill my opponent's personality. Can he interrupt with A Good Death?
I'm not really sure aout when the unstoppable trigger ends, and if a Good Death is on the action timing, or the death timing. My guess is you can't.
A Good Death Interrupt: If the action is another player's, after it destroys your defending Follower or Personality, give your target Personality +2F and Resilient, and gain 2 Honor. (Once per game per card, a Resilient card does not die in battle resolution.)
Serenity Unstoppable Battle, : Target your unbowed Samurai. Ranged Attack equal to his Personal Honor. (Other players cannot Interrupt Unstoppable actions.)
Thank you!
Other players cannot Interrupt your Unstoppable actions.
To answer your question about timing... Unlike Reactions, Interrupts are only played in the Interrupt step of the action they're interrupting. If A Good Death were a Reaction, you would play it during the action's Resolution, (immediately) after the Personality is destroyed.
However, with Interrupts, the trigger isn't a statement of when the action is played: instead, it's a statement of when to apply the delayed effect created by the Interrupt.
Note that not all Interrupts have an explicit trigger like this, nor do they all create delayed effects. For example, Absolution, as well as having no explicit trigger, negates all the effects of the action, which technically is a type of ongoing effect. Similarly, Devastating Betrayal may create an instantaneous effect, immediately changing the target of the action.