I have a 3 chi personality in play, which gains tactician, but, not the tactical advantage ability, from Aranai Sensei. If Myuken copies the tactician trait from that 3 chi personaliy who has gained tactician from Aranai sensei, would Myuken still keep the tactical advantage ability, assuming Myuken's chi is still under 3?
Aranai Sensei + Myuken
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.
I have a 3 chi personality in play, which gains tactician, but, not the tactical advantage ability, from Aranai Sensei. If Myuken copies the tactician trait from that 3 chi personaliy who has gained tactician from Aranai sensei, would Myuken still keep the tactical advantage ability, assuming Myuken's chi is still under 3?
"Tactician" is a keyword, not a trait, and copying isn't permanent by default, so he would lose the keyword (and thus, the ability) at the end of the turn which you used the copy ability.
But otherwise the answer to your question is "yes!". C-c-c-combo!!!