Is this a reaction or a trait? Can you choose when you want to bring him back or is that right away? I am confused here.
Hida Daizu
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.
Is this a reaction or a trait? Can you choose when you want to bring him back or is that right away? I am confused here.
It is a type of trait called a "triggered trait" (http://rules.l5r.com/Card_features#Traits).
Pertinent to your question is this part of the section I linked:
"Effects of triggered traits are not optional – they must happen if the trigger occurs."
Because I know you're new, and please don't take this as sarcastic condescention: Have you seen the Samurai Edition Comprehensive Rules? It's a dauntingly large document, but highly useful.
On: Hida Daizu, Hida Daizu
Hida Daizu: Is this a reaction or a trait?
It's a trait. In particular, it's a triggered trait.
If it was a Reaction, it would say "Reaction:" in front of it.
You can see more about traits here: http://rules.l5r.com/Card_features#Traits
And more on abilities here just underneath: http://rules.l5r.com/Card_features#Abilities
On: Hida Daizu, Hida Daizu
Can you choose when you want to bring him back(?)
No. From the section on traits (again: http://rules.l5r.com/Card_features#Traits):
"Effects of triggered traits are not optional – they must happen if the trigger occurs.
"A triggered trait on a given card or stronghold occurs once and only once each time that trigger occurs."
Incidentally, there is no need to post pictures when asking questions in the forum. Quite often, pictures found on the web are based on preview images, and those sometimes differ from the final, printed card.
On: Hida Daizu