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, 5 July 2009
Does the action Flanked by Nightmares itself target the personality its killing? For example if I play flanked can my opponent play strength of the bamboo to stop it.
flanked by nightmares Text Battle: If your current army has more units than the current enemy army, bow your target Shadowlands Personality: The enemy leader targets and destroys a Personality in his current army. Strength of the Bamboo Reaction: After an action targets your Hero Perosnality: Negate his destruction from the action's effects. Give him +1F
Brook Cunningham (rules official), 5 July 2009
Does the action Flanked by Nightmares itself target the personality its killing? For example if I play flanked can my opponent play strength of the bamboo to stop it.
Yes and yes.
The action targets because it uses the word "target". And Strength of the Bamboo reacts to "After an action targets", not specifying which player is doing the action's targeting, so that works.
However, if you were to have asked whether Armor of the Heavens could react to it, the second answer would have been "No", because that card reacts to "After another player targets". And Flanked by Nightmares forces the opponent to do the targeting of his own guy himself.