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.
Seat of Power:
Reaction: When an action would target on of your Clan Champion or Daimyo personalities: The action instead targets another of your legal personalities with the same clan alignment at his location.
Who chooses the targets? It isn't specified so a player is arguing that the player of the action is the one to choose the target while we play it as the owner of the Seat chooses the target.
Seat of Power: Who chooses the targets?
Actions are read from the controller's point of view. It's your action. You pick.