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, 5 June 2015
Reinforced Yari Will only attach to an Infantry Personality. This Personality cannot gain Cavalry...
I have a Cavalry Personality. Cavalry is removed with Victory Through Deference. I attach a Reinforced Yari.
1. Does the end of an effect which removed a keyword count as gaining (or attempting to gain) the keyword?
Assuming yes, and the personality remains Infantry:
2. If the above personality was a Shugenja with Interrupt the Void's Flow attached, what happens if the unit removes itself from the game the following turn? Does the Yari fail to reattach? Or would the trait from the Yari track while removed from the game?
(Void Interrupt: Negate a Battle action. Destroy this Spell. Remove the caster's unit from the game, keeping all attachments and tokens, and ignoring leaving-play effects. Return it to play before the turn ends, ignoring entering-play costs and effects)
Jon Palmer (rules official), 7 June 2015
Reinforced Yari Will only attach to an Infantry Personality. This Personality cannot gain Cavalry...
I have a Cavalry Personality. Cavalry is removed with Victory Through Deference. I attach a Reinforced Yari.
1. Does the end of an effect which removed a keyword count as gaining (or attempting to gain) the keyword?
Assuming yes, and the personality remains Infantry:
2. If the above personality was a Shugenja with Interrupt the Void's Flow attached, what happens if the unit removes itself from the game the following turn? Does the Yari fail to reattach? Or would the trait from the Yari track while removed from the game?
(Void Interrupt: Negate a Battle action. Destroy this Spell. Remove the caster's unit from the game, keeping all attachments and tokens, and ignoring leaving-play effects. Return it to play before the turn ends, ignoring entering-play costs and effects)
1. Yes. When the removal effect is done, it regains the trait, and Reinforced Yari will prevent this. - REVERSED, SEE BELOW
2. Attachments do not reattach when the unit re-enters play, so the Yari is fine. While the Yari is out of play, it is not suppressing Cavalry, so the Personality will regain Cavalry, and will be a Cavalry Personality with a Reinforced Yari when they re-enter.
Jon Palmer (rules official), 9 June 2015
This answer is being REVERSED.
1. Much like the expiration of a force bonus does not create a force penalty, the expiration of an effect suppressing Cavalry does not count as the card "gaining" Cavalry. Therefore, at the end of the turn the unit will have Cavalry and the Reinforced Yari.
2. This answer actually stays the same - the Yari does not need to "reattach", and so the Personality will have Cavalry and the Yari.