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, 24 May 2015
Myuken 3F/2C - Open: Myuken copies one keyword from your target Personality.
Aranai Sensei - Your Personalities with 3 or more Chi have Tactician. Unless they have the printed Tactician keyword, they do not have the Tactical Advantage ability.
I control Aranai, have Myuken and a 3C personality. I use Myuken's ability to copy the Tactician keyword from the 3C personality.
Has Myuken the Tactical Advantage ability?
I would say yes because "Unless they have the printed Tactician keyword, they do not have the Tactical Advantage ability." they referring to "Your Personalities with 3 or more Chi". Since Myuken only has 2C he isn't affected by Aranai's limitation.
However if he somehow gets +1C, he would loose the Tactical Advantage ability since he now would be affected by Aranai's limitation.
Did I get this correct?
Jon Palmer (rules official), 24 May 2015
Myuken 3F/2C - Open: Myuken copies one keyword from your target Personality.
Aranai Sensei - Your Personalities with 3 or more Chi have Tactician. Unless they have the printed Tactician keyword, they do not have the Tactical Advantage ability.
I control Aranai, have Myuken and a 3C personality. I use Myuken's ability to copy the Tactician keyword from the 3C personality.
Has Myuken the Tactical Advantage ability?
I would say yes because "Unless they have the printed Tactician keyword, they do not have the Tactical Advantage ability." they referring to "Your Personalities with 3 or more Chi". Since Myuken only has 2C he isn't affected by Aranai's limitation.
However if he somehow gets +1C, he would loose the Tactical Advantage ability since he now would be affected by Aranai's limitation.
Did I get this correct?
Yes, you are correct. Myuken can copy Tactician, and he gets Tactical Advantage as long as he is not 3C. If he gets a chi bonus and reaches 3C, he loses the ability.