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.
Can I use the reaction on Lion Mempo while resolving an opposed battle I won?
If so, can I then take a battle action that:
1) requires opposition?
2) does not require opposition?
Reaction: After a Personality in this battle is destroyed: This Personality copies a Battle action on the destroyed card (until the turn ends) and may take an additional battle action to perform it.
Can I use the reaction on Lion Mempo while resolving an opposed battle I won?
The Reaction is legal, but you cannot take the additional Battle action, since nothing on the card allows you to override the rule about when Battle actions are legal.