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, 9 July 2008
The scenario is as follows.
Sozen is the lone defender against Shiba Aikune xp3. Action from Shiba's player is to play Determination, and then blow up Aikune to blow up Sozen.
Question is - When a card is removed from the game, its effects can no longer go off correct? So when Aikune leaves play after paying the cost, per Determination's text, then there is no "Aikune" effect left available in the game to blow up Sozen?
Relevant Text
Shiba Aikune XP3 - Battle: Any number of times per turn, destroy a Personality in Aikune's army: Destroy two target cards opposing Aikune with no attachments.
Determination - Dark Virtue Reaction: Before you announce an action, target one of your Samurai: The action can not have its effects negated or have its targeting changed. After the action destroys any Personality, remove him from the game.
A player, 9 July 2008
Sozen is the lone defender
Who? [Mod reminder: Please use complete card titles (and Experience levels if a a card has one) when asking questions. Thanks! -LH] Assuming you mean either Hida Sozen (Experienced) or Hida Sozen (Experienced 2)...
Action from Shiba's player is to play Determination, and then blow up Aikune to blow up Sozen.
Not legal in your example. If Hida Sozen is the only card with no attachments opposing Aikune at the current battlefield, Aikune's controller is not allowed to use Aikune's Battle ability because he must be able to target two such cards. Assuming Hida Sozen is not "the lone defender" so that Aikune's action can be legally taken...
So when Aikune leaves play after paying the cost, per Determination's text, then there is no "Aikune" effect left available in the game to blow up Sozen?
No. Unless something else intervenes, Sozen is destroyed by Aikune's action's effect, then he is removed from the game by Determination's effect, even if Aikune has been removed from the game after paying his action's cost by destroying himself.
Although you can not use abilities on your cards that are not in play or in a resolution, entering-play or focusing area (see Implications of in and out of play), this rule only forbids to take new actions from such cards but it does not prevent an action from resolving after it has been legally announced, even if the card which it is on leaves play (see below, emphasis mine). The fact that Aikune lies in the "outside the game" area instead of the Dynasty discard pile doesn't matter here.
Abilities and actions, D. Action resolves: "Once the action has begun to resolve, effects that influence its ability to have been played in the first place do not influence the activation of its own effects. Example: Required targeting becoming illegal, or the card leaving play."