I have an army containing Shosuro Seibei and 3 courtiers. My opponent has Shiba Aikune Exp. 2 and a several other personalities opposing me. If he tries to use Aikune's ability, what happens? Aikune must target two personalities, but anything targetting the courtiers is redirected to Seibei.
Is Aikune's action legal? Does only Seibei die? Does Seibei's trait consider her to not be a legal target, and therefore fail when redirecting from one of the courtiers?
Does the answer change at all if the action in question can have any number of targets, such as Shuten Dojo's Fury? Can my opponent use his 4 Personal Honor personality to target all 4 of my personalities (including Seibei)? If so, what happens?
Thanks
http://rules.l5r.com/Glossary_T#Target "When multiple targets are chosen simultaneously, the same target cannot be chosen twice. This also means that when one target out of multiple, already-chosen targets is being changed, another one of those already-chosen targets cannot legally become the new target."
This means that in either case (Aikune's multiple required targeting or Shuten Doji's Fury's multiple variable targeting), once Seibei is one of the targets, his trait won't cause him to become a target AGAIN; that would be illegal, so his trait would fail.
Now, how he becomes a target is mostly up to you. If you choose all your Courtier targets and not Seibei, the active player decides which Courtier's targeting Seibei's trait triggers for (Here, "If the order of simultaneous triggers to an occurrence needs to be determined, the active player determines their order.").
The better option, whether or not you're the active player but especially if you're not, (and I'm editorializing here) is always to choose Seibei WITH the group of Courtiers. Before all the simultaneous targeting actually occurs, his trait will trigger for each Courtier (in an order chosen by the active player) and fail each time because he's already one of the chosen targets.
As a caveat, these sequences could be further complicated by the addition of Reactions such as Turn of Fortune or Shosuro Aroru. Just let the link above be your guide, as far as resolving conflicts of timing.
(Edited twice for absolute correctness; essential point and ruling remained constant, however.)