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, 27 November 2007
Soul Jar' Action:
Limited: Bow this Personality: Lose 3 Honor. Target one of your dead Personalities. He enters play, waiving costs, with a +2F/-1C token and permanently has 0 PH. After the next time this game this Personality straightens or leaves play, destroy the target.
Bayushi Kyuichi's Action:
Reaction: After an action resolves that gave a Personality a Chi penalty (including penalties from tokens): Give the Personality a -1F/-1C Poison token.
I am not sure about the timing (He enters play, waiving costs, with a +2F/-1C token) . Can I react with Kyuichi when the Soul Jar is used?
Zen Faulkes (rules official), 27 November 2007
Can I react with Bayushi Kyuichi when the Soul Jar is used?
http://rules.l5r.com/Glossary_R#Resolve: "It stops resolving when its sequence of effect activation has ended, even if the application of some effects has been delayed." Yes.