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, 28 July 2012
It seems via the wording, like the original poster was asking if: 1. His Nikaru uses his ability on another Berserker and 2. that Berserker's controller uses Halls to delay Nikaru's action and 3. the Berserker is destroyed via battle resolution, 4. can the Berserker's controller use Feign Death or would Nikaru's ability have taken effect and prevent him from performing the action.
Relevant Text: Feign Death Reaction: After the resolution of an action or a battle that destroyed a performing Personality you own: Bring him into play (in your home), ignoring costs and Honor Requirement. Bow him. Dishonor him. Lose 2 Honor.
Halls of the Forgotten Reaction: After another player's Battle action targets your Berserker: Delay its effects on him until after this battle ends.
Hiruma Nikaru Battle: Target an enemy Personality: Bow him. He may not perform actions.
Even if that's not what he was asking, I'd like to know how that pans out. I guess it would come down to whether Battle Resolution is after a Battle Ends or the final step of the battle. If it is after the Battle Ends, Would the Active player be able to take reactions before delayed effects take effect. (As he/she could choose the order in which they resolve if he could react before Halls officially wears off.)
Jon Palmer (rules official), 28 July 2012
It seems via the wording, like the original poster was asking if: 1. His Nikaru uses his ability on another Berserker and 2. that Berserker's controller uses Halls to delay Nikaru's action and 3. the Berserker is destroyed via battle resolution, 4. can the Berserker's controller use Feign Death or would Nikaru's ability have taken effect and prevent him from performing the action.
Relevant Text: Feign Death Reaction: After the resolution of an action or a battle that destroyed a performing Personality you own: Bring him into play (in your home), ignoring costs and Honor Requirement. Bow him. Dishonor him. Lose 2 Honor.
Halls of the Forgotten Reaction: After another player's Battle action targets your Berserker: Delay its effects on him until after this battle ends.
Hiruma Nikaru Battle: Target an enemy Personality: Bow him. He may not perform actions.
Even if that's not what he was asking, I'd like to know how that pans out. I guess it would come down to whether Battle Resolution is after a Battle Ends or the final step of the battle. If it is after the Battle Ends, Would the Active player be able to take reactions before delayed effects take effect. (As he/she could choose the order in which they resolve if he could react before Halls officially wears off.)
If the Berserker is destroyed by battle resolution, the battle isn't over at that point. Nikaru's effect will not have applied yet at that point, and therefore Feign Death is legal. I may have misread the original question.