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, 14 September 2011
Gojo Yurishi - Reaction: After another player's Battle action targets Yurishi: He disappears into the shadows. Move him home. If he is no longer a legal target for the action, negate its effects on him.
Flawless Assassin - Reaction: After one of your Personalities moves to or from this unit's location, if this unit has no non-Ninja Personalities or Followers: Move this unit to any location.
So the question I am posing is this: If Yurishi has a Flawless Assassin attached, and my opponent targets him with a battle action, I can move him home. THEN, if I chose to use the Flawless reaction to return him back to the battleground he came from, would he still be a target for the action when he comes back? The second half of Yurishi's reaction state that the effects get negated, so if that happens before I move him back then he can return safely.
I suspect there will be more questions about this later, since Yurishi only negates actions "on him." That means other effects that destroy attachments or units would still go off, but that, too, is a timing issue that is not obvious at face value.
Thanks,
Ryan
Brook Cunningham (rules official), 14 September 2011
If Yurishi has a Flawless Assassin attached, and my opponent targets him with a battle action, I can move him home. THEN, if I chose to use the Flawless reaction to return him back to the battleground he came from, would he still be a target for the action when he comes back? The second half of Yurishi's reaction state that the effects get negated, so if that happens before I move him back then he can return safely.
Yes, he would still be the target after moving back, and no, the effects upon him would not be negated.
Flawless Assassin reacts immediately after the movement, which occurs before the effect that checks if Yurishi is a legal target. So the Follower moves him back, and he's therefore a legal target when the check occurs, so the effects are not negated.