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.
Player A has Hida's Guidance in play and attacks player B, who's got two provinces and Fu Leng's Guidance in play.
Player A uses his Hida's Guidance and destroys his army (and the province, with its battlefield). Can Player B react with Fu Leng's Guidance to that action and (successfully) bring into play one of the personalities destroyed to pay Hida's Guidance's cost?
Player A has Hida's Guidance in play and attacks player B, who's got two provinces and Fu Leng's Guidance in play. Player A uses his Hida's Guidance and destroys his army (and the province, with its battlefield). Can Player B react with Fu Leng's Guidance to that action and (successfully) bring into play one of the personalities destroyed to pay Hida's Guidance's cost?
This question boils down to: Can you "Bring him into play... in your current army" when there is no current army?
First, this is one effect, not two. It's not "enter play and join the army" or any such thing. Thus, the "all effects are independent" rule does not apply.
Second, I cannot find any rule that says if a card cannot enter play in a specified location, it defaults to some location. (This is a rare enough situation that it might be in there somewhere, but I can't find it.)
Based on those, the effect fails because there is no current army for the Personality to enter play in.